England and Wales Court of Appeal (Criminal Division) Decisions

IN THE HIGH COURT OF JUSTICE
IN THE COURT OF APPEAL (CRIMINAL DIVISION)
ON APPEAL FROM LEEDS CROWN COURT
Mr Justice Andrew Smith
T20027338

		Royal Courts of Justice Strand, London, WC2A 2LL
		03/12/2009

Lord Justice Goldring :

1. On 30^th July 2003, following a trial at Leeds Crown Court the appellant was convicted of conspiracy to commit arson with intent to endanger life (Count 2) and 8 Counts of manslaughter (Counts 3-10). He was sentenced by Mr Justice Andrew Smith to 14 years imprisonment on Count 3 and 18 years imprisonment on the Counts of manslaughter. He had previously pleaded guilty to a Count of conspiracy to commit arson (Count 11) for which he was sentenced to 2 years imprisonment. All sentences were to run concurrently. The jury acquitted him of murder on Counts 3 to 10. On the judge's direction he was found Not Guilty of conspiracy to damage property (Count 1).
2. There were co-defendants. Shaied Iqbal was convicted of conspiracy to commit arson (Count 2) and of murder on Counts 3 to 10. He had pleaded guilty to Count 1 (conspiracy to destroy property). Shakiel Shazad was convicted on Count 2 and of manslaughter on Counts 3 to 10. He was convicted also on Count 11. Arif Siddiq pleaded guilty to conspiracy to destroy property (Count 1). So too did Intizar Hussain. It is unnecessary to refer to those who were acquitted.
3. The issue in the appeal is whether fresh scientific evidence relied upon by the appellant renders the convictions on counts 2-10 unsafe.

The facts

4. At shortly before 2am on 12^th May 2002, 40, Osborne Road in Huddersfield was deliberately attacked by fire. Petrol, and petrol bombs consisting of milk bottles filled with petrol, were used. Most of those inside were killed. Eight people died. They included children. It was at 1.57am that emergency calls in respect of the fire were first received.
5. The occupants of the house were members of the Chishti family. They had been asleep when the fire had been set. Although the trial took some weeks, the basic issues were not complicated. The motive for the attack was said to be revenge. Iqbal believed that one of the occupants of the house, someone called Ateeq-Ur-Rahman, had been spreading rumours that he was in a relationship with a woman called Mobeen Mumtaz. The prosecution alleged that the appellant and some of his co-defendants were recruited by Iqbal to set light to the house. We shall concentrate on the evidence insofar as it was alleged to implicate the appellant.
6. On 11^th May 2002, in the hours leading up to the fire, Iqbal telephoned the appellant. He asked if he had a petrol container. He said that he did. He had had it for a couple of months having bought it from a petrol station with Iqbal's credit card, he said for no particular reason. Prior to that night it had not been used. Iqbal asked him to fill the container with petrol. The appellant said he and Intizar drove to a garage nearby in Huddersfield on Lockwood Road ("Lockwood's"). The appellant filled the container with petrol. They went to a garage called Sam's Autos in Viaduct Street in Huddersfield. The appellant gave Iqbal the container of petrol. It was somewhere past 10.30pm. The appellant remained there for about 4 hours off and on. He said in evidence he had been inside only for very brief periods. There was, said the appellant in evidence, conversation in which Iqbal said something about somebody "fucking with his girl", that "the motherfucker fucked with the wrong person" and that he was going to deal with him.
7. According to Siddiq, (who had pleaded guilty to Count 1 and gave evidence for the prosecution), Iqbal said they were going to set light to a car. The appellant said he had heard Siddiq shouting for some milk bottles. Shazad put on rubber surgical gloves. He took handfuls of metal fixing nuts from a container in the garage which he told them would make the fire burn quicker. He put the nuts inside milk bottles. The milk bottles were partly filled with petrol. Pieces of cloth were cut up and stuffed into the necks of the milk bottles. According to Siddiq, Iqbal and Shaied Mohammed placed the milk bottles into a cardboard box in the back of a black Nissan Micra. According to Siddiq and Intizar Hussain, (who also pleaded guilty to Count 1 and gave evidence for the prosecution), the petrol bombs were going to be thrown at a car parked outside 40 Osborne Road. Those to be involved in the attack on the car were Iqbal, Shazad, the appellant and Shaied Mohammed. Surgical gloves were taken to lessen the risk of fingerprints being found, they said.
8. According to the appellant, at some point when still at the garage, Iqbal said, "let's go and see if my man's awake." The appellant said that he didn't know what Iqbal was talking about. Iqbal, Shaied Mohammed and Intizar Hussain went in Intizar's car. About 20 minutes later they returned. A light was on at the house. Iqbal spoke of going on a mission; he said, according to the appellant in evidence, "we're going to go and burn somebody's car down;" that the car they were going to burn belonged to Ateeq.
9. A police car came down the road. Iqbal shouted to hide the petrol bombs. The appellant said that was the first time he knew about them. He had had nothing to do with the making of them. He agreed that some of the 5 litres of petrol that he had purchased from Lockwood's had been used in making the petrol bombs. In other words, there is no doubt that at least some of Lockwood's petrol was in the petrol bombs.
10. Iqbal put 4 bottles into the Micra car. The appellant, as he said, put his container with the remains of the petrol in it, in the boot. Shaied Mohammed put a metal bar in the boot. The appellant said did not know what the items were to be used for or that the objective was set fire to more than just one car.
11. The appellant and Iqbal went off to put some petrol in the Micra. The appellant paid for it. He said he did so because he was asked to. On their return to Sam's Garage, Iqbal and Mohammed again went in the Micra to see "if my man's awake or not", according to the appellant. On their return Iqbal said that the lights were off. One of them said, "let's go;" the appellant said he thought that meant go and burn the car. He said he did not know where the car was and had never before heard of 40, Osborne Road.
12. Both Siddiq and Intizar Hussain said that the petrol bombs were going to be thrown at a car parked outside 40, Osborne Road.

What happened at Osborne Road

13. They drove off in 2 cars, the Micra and Intizar Hussain's Honda Accord. They parked near to Osborne Road. When they got there, the appellant said that he was told his role was to pour petrol over cars outside Osborne Road and set light to them. He agreed. Iqbal, Shaied Mohammed, Shazad and the appellant went to Osborne Road. Intizar Hussain and Siddiq remained in the motor cars. The petrol bombs, the container of petrol and the crowbar were taken out of the boot. The appellant took the container. He and the others were given some gloves. He said he thought the others would not go through with the plan. He was prepared to pour petrol onto a car in the street and set light to it. According to the appellant when they arrived at 40, Osborne Road, Iqbal put the milk bottles on a wall. The appellant said he asked Mohammed which car he was to burn. He was told to set fire to all 4 cars outside the premises. He walked up to one of them and started to pour petrol over it. As soon as he did so he heard a bang. The front window of 40, Osborne Road was being smashed by Mohammed with the metal bar. The petrol bombs on the wall had been lit. Iqbal was by them. Iqbal threw a petrol bomb through the window. He then threw another one. Mohammed picked one up and threw that through the window. Iqbal threw another one in. The petrol bombs had gone into the living room. It was on fire. The appellant said he was scared and ran off. By then, he had not done anything. His petrol container still had a nozzle on it. He said he did not pour any petrol into the house.
14. Abdul Majeed lived at 21, Osborne Road. He was disturbed by the noise coming from his parents' house. He looked out and saw the living room window of the house was broken. There were flames inside. What he saw is apparent from the cross-examination of the appellant by the prosecution.

"[Abdul Majeed] said he could see the backs of men…? Yes.

No. 1 man was on the grass next to the bush…? Yes.

…He was 2 yards from the window when I saw him. He was Asian…He threw something at the window. The window was broken. The room was on fire. I could see flames…?

[The appellant said number 1 was Mohammed].

"…[Abdul Majeed] said that No 2…was on the pathway in the garden closer to the gate, quarter of the way in from the gate…He also threw something into the front room window. It went in. The fire increased…

[The appellant said number 2 was Iqbal].

[The appellant said Shazad was behind him standing by the gate]. Shazad did not throw anything.

…[Abdul Majeed said in respect of man number 3 that] "I assumed he put something in the letter box, because inside the door I could see the flames going up. Man number 3 was close to the door, the door was closed." Can you help us with who man number 3 is? No…it was not me."

15. The appellant accepted that someone had poured petrol through the letterbox. He agreed that only he had a container from which 2 to 3 litres of petrol could have been introduced into the house through the letterbox and that he had flung the container away. He said had the petrol in his possession throughout. When he left the scene it had petrol in it and the nozzle was attached. No petrol was in fact poured to any car in 40 Osborne Road. When he threw the container away petrol dribbled from it. Then it poured out.
16. According to Abdul Majeed, the four men ran off together.

Events after the attack

17. The appellant threw away the petrol container and the surgical gloves. They were later found nearby. The appellant's fingerprint was on the container. His fingerprint was on one of two pairs of 5 pairs of gloves found. The gloves with the appellant's fingerprint on it showed traces of petrol containing an additive to petrol known as MTBE.
18. Although he was very angry about what had happened, the appellant said he did not contact the emergency services. He thought someone he had seen would do so.
19. Siddiq said that the appellant and Shazad got into Siddiq's car. The appellant was swearing and said "what the fuck happened? Why didn't you wait for me? These lot threw one through the door and one through the window and never gave me a chance to do the car." If true, those words are evidence of, among other things, a joint enterprise by the four of them to attack the cars and the house.
20. The appellant said that next day Iqbal and Shazad came to his house. The appellant learned that 7 or 8 people had died in the fire. He said he had been upset and crying when he learned that. A group, including Iqbal, Shazad, Intizar Ahmed and the appellant went to Bradford. Iqbal suggested they should get their alibis together. The appellant said he told Iqbal he didn't need one as he played no part in burning the house. He said in evidence his intention was to put it straight to the other men that he had had nothing to do with death of 8 people in the fire. He said that after the attack he consorted with those involved because he wanted to sort it all out. He was afraid to go to the police.
21. The appellant destroyed his telephone SIM card and got rid of his mobile phone. He caused his clothing and his Nike trainers to be burned.
22. The appellant said at no time did he enter into any agreement to attack the house, to injure or cause the death of any person. He played no part in any such scheme.

Iqbal's evidence

23. Iqbal denied he had knowledge of the true nature of the mission. He said, among other things, that the appellant had assisted in the preparation of the petrol bombs. The appellant would be the one who would pour petrol through the letter box. He said he saw the appellant drawing the petrol container back from the letter box. The appellant placed two of the lit petrol bombs inside the living room through the window. As they ran down an alleyway the appellant threw away the petrol container.

The appellant's arrest and events thereafter

24. He was arrested on 14 May 2002. He made no comment when interviewed. He was subsequently charged. He was interviewed again in May and July 2002. He made no comment.
25. On 9 June 2002 the appellant was visited in prison by a man called Iklaq Hussein. He told Iklaq Hussein that he had given the petrol container to Shakiel Shazad two days before the fire.
26. Prior to 27 November 2002 the drivers gave their accounts. The appellant asked to be interviewed again. He gave an account consistent with that of the drivers: that the only agreement to which he had been party was to set light to vehicles.

The scientific evidence

27. The prosecution relied upon Dr. Swann and Dr. Large. The defence relied on Dr Candy.

The undisputed evidence

40, Osborne Road

The seats of the fire

28. An accelerant was used. It was believed to be petrol. There were two separate seats of fire. The first was in the living room under the window and behind the settee. The living room window had been broken before the fire had started. Milk bottle glass had been found in the living room. Glass was also found outside the house in the front garden. At least 4 bottles had been used.
29. The second seat of fire was in the hallway. Only the letterbox remained of the UPV front door. The most intense area of burning in the hall was in the area of the doormat recess inside the front door. There was intense burning all the way up the banisters and the stairs. There was no sign of milk bottle glass in the hall or outside in the area of the front door.

The hallway

30. Before the fire in the hall was started an accelerant such as petrol was introduced. It was ignited a short time after it was introduced; Dr Candy suggested probably within 2 or 3 minutes, not more than 5. Dr Swann said that for the fire to have had the intensity it did, the petrol would have had to have been present for a sufficient period of time.

MTBE and TAME

31. MTBE and TAME are petrol additives. Some petrol contains only MTBE. Some contains only TAME. Some contains both, some neither. It was accepted at the trial that the Shell petrol sold by Lockwood's (and bought by the appellant) contained MTBE. It did not contain TAME. Mr. Jerome Lynch QC, who represents the appellant, accepts that in this appeal.

Some exhibits seized

32. Metal fixing nuts were found in the living room and in the garden. They were consistent with those found at Sam's Garage.
33. A fixing nut (SAM/10) was found to the left of the front door. It revealed the presence of MTBE. The respondent no longer relies on the presence of MTBE on this nut.
34. Samples of petrol were taken from the living room and from the base of the milk bottle (SAM/31) found in the living room. Analysis revealed the presence of MTBE. That is not surprising in the light of the rest of the evidence.
35. There were traces of petrol detected in the debris in the hallway. MTBE was detected in the space at the top of the bags (the headspace) containing three samples from the hallway: SAM/6 (burnt debris including the letterbox from the doorway), SAM/16 (carpet and underlay from the hallway) and SEL/15 (some floorboard from the hallway). Dr. Large said about SEL/15:

"Close inspection of the data revealed the presence of some petrol containing isooctane [a component of petrol], MTBE and possibly also a trace of TAME."

36. SAM/13 and SAM 17, two other samples from the debris in the hallway, indicated neither MTBE nor TAME.

The source of the TAME in SEL/15

37. The experts considered the possible origin of the TAME in SEL/15. They all rejected the suggestion that it might have come from petrol walked into the house by firemen or others attending the scene or that it came from shoes in the hall. Although not accepted formally, that is effectively the position adopted in this appeal. Dr Large (for the prosecution) considered whether the TAME might have come from a milk bottle that had previously contained petrol with an additive but concluded that petrol would not last for the required time in a container as petrol evaporated quickly.
38. The explanation supported by the expert witnesses was that there might have been two separate petrols introduced into the hall: one with TAME, one without. In Dr Large's opinion there would have been much more of the petrol without TAME than of petrol with it. The petrol without it (and with MTBE) could have come from the green container. The petrol with TAME could not. Dr Candy (for the defence) was of the opinion that the trace of TAME in the one sample from the hallway was likely to have come from petrol recently introduced into the house within 24 hours before the fire. He too was of the opinion that it was possible that two kinds of petrol were introduced into the hallway.
39. The traces of petrol found in the container which the appellant had throughout the incident revealed the presence of MTBE, but no trace of TAME.

The disputed scientific evidence at trial

40. Dr Swann experimented with pouring liquids through a letterbox similar to that at 40, Osborne Road. He found that it was possible to pour an accelerant from a normal petrol container such as the appellant's without much spillage unless the container was withdrawn before it was empty. He found it was not possible to pour more than a tenth of a pint of liquid from a bottle and that it was likely that liquid so poured would have spilled down in front of the door. It would have been a time consuming way to introduce an accelerant from bottles: a litre of petrol would have required 20 full bottles. Dr Candy said that 2 or 3 litres might have been introduced.

How the petrol was ignited

41. Dr Swann said that if poured through the letterbox leaving no drops, it would have been possible to ignite by lighting a taper and putting this through the letterbox. However, some drops might run down the door and onto the stones beneath and on to the doorstep. That could have been lit with a naked flame such as a cigarette lighter, match or a taper. The petrol on the outside of the door would have ignited and burned through to the inside, thereby igniting the petrol inside.
42. Dr Candy agreed that was possible. He considered that the picture of someone approaching the door furtively and introducing petrol that way did not appear to fit the circumstances. It was more likely that a petrol bomb had been thrown at the front door. The spillage of petrol in the door area caused the fire from the bomb to be drawn through the letterbox into the hall which then ignited the accelerant inside. Dr Candy said that the location of the metal nuts (found away from the living room windows and by the front door), suggested to him that a petrol bomb might have been launched at the front door, although no bottle glass was found in the area of the door.
43. In opening the case, the prosecution suggested that one of the defendants used the petrol container to pour petrol through the front door without pointing specifically to the appellant. In the summing up the judge said that:

"[The prosecution] say that you can be sure that the rest [of the petrol from the container] was poured through the letterbox, and that you can reject [the appellant's] account of what happened in Osborne Road."

44. The defence submitted that no one contradicted the appellant's account of what happened in Osborne Road. It relied upon the presence of the TAME in SEL/15 as indicating that petrol which could not have come from the appellant's container had been introduced through the front door. That suggested another source of petrol having been poured through the letterbox that night. As for the MTBE, that might have come into the hall on the shoes of Mohammed (upon whose shoes which were seized after these events, was found evidence both of MTBE and TAME). The presence of petrol with MTBE and without TAME was explicable by Dr Candy's opinion that one of the milk bottles could have been thrown at the front door.

What the judge said about the scientific evidence

45. As Mr. Lynch accepts, the judge clearly and fairly summarised the expert evidence. He put those areas in which there was disagreement into context. As he put it [46/10]:

"I have already said it is for you to decide whether it assists you to reach your verdicts to explore this difference of opinion between the experts. If it does, then the considerations I have been putting before you are no doubt matters that you will weigh. If it does not, and you so decide, then you can leave this question aside, but Mr. Swift [the appellant's defence counsel] in particular asks you to pay careful attention to this evidence, for reasons that I will come back to when I remind you of the [appellant's] defence…"

The direction on joint enterprise on the counts of murder

46. As relevant to the appellant, the judge said:

"If [a defendant] was there when someone else or other people committed the offence, and what was done was fundamentally different from anything he realised might be done, he is not responsible for their actions…if a defendant was there to help set fire to a car, and he did not realise, or might not have realised…that the house was to be burned by his companions, that defendant will not be responsible…for the burning of the house, and…the deaths that resulted…Unless, taking each of these three defendants separately, you are sure either that he was personally involved in burning the house, or that he was party to a venture to burn the house, and realised that the others, or one of the others, might do it, you must find him not guilty of the murder charges. That is because, in those circumstances, you could not be sure that he was a participant in the venture that caused the deaths."

47. In other words, as the judge left the case to the jury, it was not necessary to resolve the areas of disagreement between the experts, neither was it necessary, in order to convict the appellant, for the jury to be sure that he poured petrol through the front door. The conviction of Shakiel, who on the appellant's evidence was further away from the house than the appellant, and did nothing directly as far as setting the fire was concerned, must have been on the basis of a joint venture, in which those who left the cars and went together to Osborne Road, took part.

The grounds of appeal.

48. Mr. Lynch's submissions can be encapsulated in the following way. On the basis of the fresh evidence, (which we have heard de bene esse), it is clear that all the previous experts failed to consider possible contamination of the exhibits taken from the hallway. Once the jury concluded, on the basis of what it now transpires was flawed expert evidence, that the appellant introduced petrol through the letterbox, it is inevitable that they would not believe anything he said about his state of mind; about the nature of the venture in which he was participating.
49. Mr. Lynch accepts that the petrol sold by Lockwood's contained MTBE. That petrol was put into the milk bottles (which could explain the presence of MTBE in samples of the milk bottles from the sitting room). It would explain the presence of MTBE in the petrol in the container which the appellant took to the scene. However, submits Mr. Lynch, there was no reliable evidence that petrol containing MTBE was introduced through the front door. The finding of MTBE in exhibits from the hall might be due to contamination. If the finding of MTBE in the area of the hallway was real, its conjunction with TAME (in SEL/15) rules out petrol from the container as a source. In so submitting, the appellant relies on the evidence of Mr. Howarth, an expert in the field of incident reconstruction and fire investigation, and, to some limited extent, on the evidence of Ms. Peplar, a consultant with M-Scan, who has instructed by the respondent. Mr. Lynch does not accept Ms. Peplar's conclusions in significant respects. (Dr. Large, who was at M-Scan, died some years ago).

Ms Peplar's graph

50. Ms. Peplar has helpfully provided the court with a graph entitled "MTBE peak area corrected." It sets out what she describes as the "Normalised relative concentrations of MTBE within the headspace of the exhibits…" The graph is simply a means of comparing the amounts of MTBE as between one exhibit and another on a uniform basis. It does not set out absolute quantities. Although as a graph it suggests substantial differences in amounts of MTBE as between one exhibit and another, Ms. Peplar accepts that those comparative amounts are based on what in every case are very small traces of MTBE. Mr. Howarth emphasised how small the traces were. He suggested that it would not be appropriate to rely on the relative differences, which he described as completely negligible. Ms Peplar disagreed, but indicated that a tolerance of plus or minus 30% should be used in respect of levels illustrated.
51. Although we are conscious of the points made by Mr. Howarth, in our view, provided the very generous tolerance of plus or minus 30% is taken into account, it is appropriate to rely on the relative amounts of MTBE as between different exhibits as spoken to by Ms. Peplar. The original analysis, upon which she relies, was completed by Dr. Large using specialist equipment in a laboratory experienced in dealing with the sort of analysis of the exhibits carried out here. We accept Ms. Peplar's evidence to that broad effect.

Contamination

52. Mr. Howarth's opinion is that is that there is evidence that the presence of MTBE in the exhibits from the hallway was, or may have been, a product of widespread contamination. He bases his opinion in particular on a series of control samples which were analysed by Dr. Large. A control sample is a sample of air from an area (for example the scene) to show (in that case) that the scene, or the sort of bags used to remove items from the scene, was free of contaminants. Ideally, there would, in the present context, be no MTBE (or petrol) in such a control bag. Mr. Lynch does not pursue any suggestion that the possible source of any contamination was the nylon bags which were used.
53. The control bags in particular relied upon by Mr. Howarth were:

(1) CE/45, a control sample taken, it seems, on 27 May 2002 at Huddersfield Police Station. It remained in the store room of the police station until 24 July 2002, when it was sent to the M-Scan laboratory.

CE/45 was found to contain MTBE, TAME and white spirit.

(2) SAM/2, a control sample taken on 12 May 2002 from outside 38 Osborne Road. It remained in the store room of the police station until 14 May 2002, when it was sent to the FSS laboratory, where it remained until 14 June 2002, when it was returned to the police store room where it remained until 16 June 2002, when it was sent to M-Scan.

SAM/2 was found to contain MTBE, TAME and white spirit.

(3) SEL/2, a control sample taken on 13 May 2002 outside 40 Osborne Road. It remained in the store room of the police station until 14 May 2002, when it was sent to the FSS laboratory, where it remained until 14 June 2002, when it was returned to the police store room where it remained until 16 June 2002, when it was sent to M-Scan.

SEL/2 was found to contain MTBE and white spirit.

(4) DSS/1 was a control sample taken in room 5 of the Forensic Science Service ("FSS") laboratory on 14 May 2003. It was sent to Huddersfield Police Station on 14 May 2002. It remained there until 14 June 2002, when it was sent to M-Scan.

DSS/1 was found to contain MTBE.

(5) DSS/2 was a control sample taken in room 29 of the FSS laboratory on 21 May 2002. It was sent to Huddersfield Police Station on 22 July 2002. It remained there until 24 July 2002, when it was sent to M-Scan.

DSS/2 was found to contain MTBE.

(6) DSS/3 was a control sample taken in room 5 of the FSS laboratory on 19 July 2002. It was subsequently sent to Huddersfield Police station. It was sent to M-Scan on 24 July 2002.

DSS/3 was found to contain MTBE.

54. We shall take each or each set of exhibits in turn.
55. Ms. Peplar accepted that the air in the police storeroom was to some extent contaminated. CE/45 reflected that. She explained how that might have happened. Between 24 May 2002 and 26 February 2003 there was kept in the storeroom AG/2, a fuel sample taken from a BMW. It was found to have leaked into its nylon bag. It was never analysed. The leak was noticed when a second sample of petrol (AG/3) was taken from another BMW. As far as Ms. Peplar knows, that was the only leak from a bag. Because there had been the leak from AG/2, CE/45 was taken, as seems to us most likely, in the police storeroom. In Ms. Peplar's opinion the nylon bag packaging of AG/2 was the most viable source of cross-contamination of CE/45. CE/45 gave a benchmark for assessing the level of possible contamination of other exhibits by AG/2 at the police station. She therefore has disregarded those exhibits in which the concentration of MTBE is the same or less than in CE/45, plus or minus 30%. That would rule out SEL/15 as having any significance. It would also rule out another hallway exhibit to which we have not so far referred, SAM/18 (the wooden floor and carpet from the hallway). Of the exhibits in the hall which contained MTBE, that would leave in SAM/6 and SAM/16.
56. In Mr. Howarth's opinion that will not do. CE/45 contained contaminated air. That meant the air in the police store contaminated. Other items in the store could have been. It could not be said whether the source of that contamination was by ingress of a liquid, into the largely impermeable nylon bag or was airborne; that is to say, vapour out of one bag and into another. It could not be said how near the source of the contamination the air in CE/45 was taken. The further away it was, the less would be the extent of contamination from that source. CE/45 could understate the extent of contamination.
57. Further, CE/45 contained white spirit. White spirit would not be a component of petrol (for example from AG/2). That suggests another source of contamination. Ms. Peplar agreed said that she could not determine the source of the white spirit in CE/45.
58. In Mr. Howarth's opinion, the most appropriate ceiling should be the most contaminated item, namely SAM/2. That would rule out all the items from the hallway. It was significant, in Mr. Howarth's opinion, that CE/45 and SAM/2 shared the same three constituents. It suggested contamination in the storeroom from more than one source containing those constituents.
59. In Ms Peplar's opinion CE/45 was less likely to have been contaminated by a liquid. The contents of CE/45 were present in the storeroom. There was no evidence of front end loading (see paragraph 61 below). The absence of front end loading suggested that the source of the contamination resulting in the finding in respect of CE/45 was not far away from where CE/45 was taken. In other words, CE/45 represents a safe benchmark.
60. In Ms. Peplar's opinion SAM/2 was not contaminated at all. Although taken as a sample, it amounted to real evidence. SAM/2 was taken at the roadside at the rear of the scenes of crime van at 10.50 AM. What was captured in the bag came from the environment at the time.
61. Ms. Peplar excluded cross-contamination at the police station as the source of the contents of SAM/2 because of the absence of what she described as front end loading. She explained what she meant. If there is cross-contamination by vapour from one nylon bag passing into and contaminating another nylon bag, she would expect the most volatile components of petrol to migrate "preferentially" from the first bag to the second. That would be reflected by the contaminated bag having a disproportionate amount of most volatile components. SAM/2 did not. It revealed a petrol trace consistent with a real sample.
62. Although Ms Peplar made plain her opinion regarding front end loading in her report, Mr. Howarth was not able to deal with it.
63. As to the white spirit, Ms Peplar indicated that it could come from a variety of sources, the most common of which was brush cleaner.
64. Ms Peplar's opinion regarding SEL/2 was the same as SAM/2. She however went back on some suggestions made in her report. First, she accepted that she had mistakenly believed that SAM/2 contained TAME. That was a misreading of the evidence. (Mr. Howarth too did not appear to pick this up in his reports). Second, in her report she had said that the slightly lower reading regarding SAM/2 as compared with SEL/2 in what she thought was the same specific location, indicated the evaporation over time of a petrol spillage (of the same petrol). That was "highly significant" as an indication that SAM/2 and SEL/2 were real results. She was plainly wrong about that. The constituents of the two exhibits were not the same. They were not collected from the same place. She stood by what she had said regarding front end loading and the reality of results. She would have expected different profiles if the results were due to cross-contamination. She thought it "extremely unlikely" that contamination in the storeroom could explain the SAM/2 and SEL/2 results.
65. Ms. Peplar suggests there is another indicator of the absence of widespread contamination such as suggested by Mr. Howarth. SAM/6, which contained MTBE, was taken at 13.15 on 12 May 2002. SAM/13, which was seized at 13.55 from an area in the hallway where petrol would be expected, contained no MTBE. SAM/16, which contained MTBE, was seized at 14.10. SAM/17, again from the same broad area, was seized at 14.15 and contained no MTBE. If there was contamination, suggests Ms. Peplar, how is it that SAM/13 and SAM/17, taken from similar areas at about the same time are not contaminated with MTBE?
66. Ms. Peplar makes another point. The absence of residue on SAM/13 and SAM/17 are apparently real results. The presence of MTBE on SAM/6 and SAM/16 are similarly real results. It suggests that MTBE was introduced into the hallway.
67. Moreover, if SAM/2 and (as she believed at the time, SEL/2) were a product of contamination, the petrol that contaminated them was different from that on SAM/6 and SAM/16.
68. In our view, although there were unsatisfactory aspects to Ms. Peplar's evidence, it seems to us she made a number of powerful points which rebutted the suggestion of widespread contamination advanced by Mr. Howarth.
69. First, we accept her evidence regarding front end loading and SAM/2 and SEL/2. In our view these exhibits reflect the reality at the time when they are taken. They are not contaminated. There is no basis for using SAM/2 as a benchmark.
70. Second, if there were widespread contamination, in particular of the items from the hallway, we would expect SAM/13 and SAM/17, taken from the same area within a short space of time, similarly to be contaminated. They were transported and/or stored with the other exhibits. SAM/13 and SAM/17 have every appearance of being real results. That suggests that the findings in respect of SAM/6 and SAM/16 are similarly real results.
71. Further, the absence of such components in SAM/48 (soil collected between the door and window of 40 Osborne Road) suggests that cross-contamination had not occurred.
72. Third, given the very wide margin of error taken into account by Ms. Peplar, we are persuaded that she is right about taking CE/45 as the benchmark for possible contamination.

DSS/1, DSS/2, DSS/3

73. We deal with these separately, for reasons which will become apparent. In our view, there is nothing to suggest that these exhibits played any, or any significant, part in possible contamination of the hallway exhibits, the issue in this appeal.
74. These are 3 control bags from FSS. Their contents were, as we have said, obtained at FSS on the different dates, in the first two cases when exhibits containing MTBE (at a lower level than DSS/1 and 2) were being opened. DSS/3 was taken because of Dr. Large's findings at M-Scan in regarding DSS/1 and 2. Dr. Large in his report said that they indicated:

"Low level gasoline contamination in working atmospheres."

75. Mr. Howarth suggests the contamination might have occurred at the police station or the FSS laboratory. Ms. Peplar suggests that logically the source of contamination in these exhibits was different from possible contamination of other bags in storage. Petrol in the environment at FSS was a distinct possibility.
76. In our view, as Dr. Large originally suggested, it is highly likely that there were traces of petrol in the atmosphere at FSS when these samples were taken. It seems to us as a matter of common sense almost inconceivable that the findings in these three exhibits had anything at all to do with the police station. Indeed, DSS/3 was only in the police station for one day. These findings do not suggest widespread contamination such as advanced by Mr. Howarth. They do not, as it seems to us, affect the validity of the findings regarding the exhibits from the hallway.

Some other matters mentioned by Mr. Howarth in his reports

77. A number of other possible sources of contamination were mentioned by Mr. Howarth in his reports. Some seem to us far-fetched. They were not emphasised by Mr. Lynch. We mention some of them merely in outline for completeness.
78. He suggested possible contamination at M-Scan, the possible use of contaminated bags, widespread environmental contamination at the scene (for example by generators or vehicle engines running nearby or upwind), during transport between these parties and possible contamination from laboratory solvents.
79. He disagreed with Dr Large's belief that nylon pouches were normally considered impermeable to the migration of vapours. Although he did not check for front-end loading, he said that oxygenated compounds such as MTBE and TAME, which are both highly volatile, may pass through nylon more easily than other components of petrol. He said that no assessment of the suitability of nylon bags for MTBE or TAME was apparent in the literature. He said that it could not be ruled out that the findings relate to no more than background levels of MTBE and/or TAME. MTBE has been shown to accumulate in air ground water and occasionally in drinking water.
80. These further suggestions, as we say, not vigorously pursued by Mr. Lynch, are rejected by Ms. Peplar. The amounts of petrol in the air were insignificant. Laboratory solvents could not explain the findings. The amounts were insignificant. There is nothing to suggest the nylon bags were contaminated prior to use. Widespread environmental contamination of the scene by generators or vehicle engines running nearby or up wind could not explain the findings. If there was such contamination it should be apparent at the same level in all the samples from the scene and is not. Further, she would not expect to detect high levels of airborne petrol vapour unless a person was actively using petrol in the immediate vicinity of where the samples were recovered. In support, she cites an American study.
81. Ms. Peplar accepts that it is possible that MTBE may pass through nylon bags more easily than complete (non-polar) components of petrol. There was no instance where MTBE was detected on its own. Other petrol components were also present.
82. We accept Ms. Peplar's evidence in respect of these matters.

The absence of Shell carrier fluid in the hallway in conjunction with the presence of TAME

83. Mr. Howarth's opinion is that "the link to [the appellant] (i.e. the fuel from Lockwood Road) is severely limited by the absence of Shell carrier fluid in the hallway and the presence of TAME." Ms Peplar disagrees that the absence of the carrier fluid detracts from the link to the appellant's petrol since its presence in the hallway may be masked by background interference.
84. What undoubtedly is the case is that the appellant brought to the scene petrol which contained MTBE and MTBE was reliably present in the hall, as we find.
85. In short, for the reasons we have given, we do not accept widespread contamination as suggested by Mr. Howarth. In our view, there is evidence of the presence of MTBE in the hallway which may be relied upon. The extent of that evidence is less than was suggested to the jury. The jury did not know about the implications of CE/45 and the leak from AG/2. There was no consideration at trial of the source of the possible contamination by white spirit.
86. The jury knew about the presence of TAME in SEL/15. (Although, on the basis of CE/45 that finding is unreliable, we shall take it into account in the appellant's favour). The jury was in terms addressed on the incompatibility of TAME with the contents of the petrol container.

Our conclusion

87. That then is the background to the fresh evidence. It is relied upon by Mr. Lynch in the way we have indicated. The flawed evidence (as he submits it was) concerning MTBE in the hall would or might have led the jury to disbelieve the appellant when he claimed he participated in a joint enterprise merely to damage cars. In that way the fresh evidence renders the convictions unsafe.
88. We cannot agree.
89. First, the case was not left by the judge to the jury on the basis that they could only convict if they concluded the appellant had poured petrol from his container through the front door. The direction set out above is quite clear. The case was left to the jury on the basis that the jury could convict each of those who left the car if they were sure the defendant in question participated in the joint enterprise.
90. Second, it seems to us clear that the jury were of the view that those who left the cars, armed as they were with four petrol bombs, a crowbar and, in the appellant's case, a container of petrol, were on a joint venture to attack both cars and house. The four arrived together. They left together. The conviction of Shakiel, who on the appellant's evidence was further away from the house than the appellant, and did nothing directly as far as setting the fire was concerned, suggests that.
91. If so, whether or not the appellant was the person who poured the petrol through the door was irrelevant.
92. Third, the evidence concerning MTBE and TAME was left to the jury in a way which made it clear that while they could take it into account, it was not necessarily something they were bound to. That was no doubt because of the uncertainties due to the presence of TAME.
93. Fourth, there was a formidable case against the appellant which had nothing at all to do with whether or not he poured petrol through the front door (although he on the evidence was the only one of those present with a container of petrol). We have set it out above and will not repeat it.
94. Fifth, for the reasons we have explained, there remains in our view reliable evidence of the presence of MTBE in the hallway.
95. Sixth, the presence of TAME in the hallway as a means of questioning the source of the petrol was a live issue for the jury. As we have said, in the light of the judge's direction regarding the expert evidence, it may well be it was not something they felt it necessary to resolve.
96. In the circumstances, while we are prepared to admit the fresh evidence under section 23(2) of the Criminal Appeal Act 1968, we are satisfied of the safety of these convictions and dismiss the appeal.