Editor’s Note

This article refers to the injustice suffered by the late Annette Hewins and Donna Clarke and Denise Sullivan and also the victims of the arson that claimed their lives: Diane Jones and her infant daughters, Shauna Hibberd and Sarah-Jane Hibberd. It and further articles relating to that injustice are being published on this site because of the connection to athletics, which will be made clear in future articles.

The Editor

By Satish Sekar © Satish Sekar (October 18^th 2025)

Unleaded?

At first, the fire that claimed the lives of Diane Jones and her infant children, Shauna and Sarah-Jane Hibberd in the early hours of October 11^th 1995 was thought to be accidental – it wasn’t. Traces of petrol was detected, especially on samples of carpet recovered from the scene of the crime. Tests for constituents of the petrol established that there was no evidence that the petrol had been leaded in circumstances where there would have been proof if it had been leaded.

Traces of toluene and the xylenes (m-xylene, o-xylene and p-xylene) were discovered,[1] but Tetraethyl lead (TEL), the leaded component of petrol was not – this was very significant because TEL had a higher boiling point, 200° Celsius, than both toluene and the xylenes. That meant that the carpet sample which had traces of petrol on it – it smelled strongly of petrol months later – could not have reached the boiling point of TEL as it had not reached the lower temperatures required for toluene and the xylenes to evaporate.

Nor were there traces of the lead scavengers,1,2-Dibromoethane, aka Ethylene Dibromide (EDB), which boils at 129-133° Celsius or 1,2-Dichloroethane (EDC)[2], which boils at 84° Celsius. EDB had a higher boiling point than toluene, which boils at 110.6° Celsius, so if it had been leaded petrol, it would be expected that Ethylene Dibromide would have been detected – it wasn’t and nor were any of the compounds, which include Lead-Dibromide and Lead-Dichloride, that would have been formed by the chemical reactions that the antiknock constituents of the petrol were designed to ensure.

Leaded petrol has now been phased out due to its detrimental effects on health.

Squaring Another Circle

The importance of all this is that there was no evidence whatsoever that the petrol used in the arson was leaded and the investigation proceeded for several months on the basis – justified by the scientific evidence – that the petrol used to set the fire was unleaded. At first, this was no problem, but eventually the police discovered proof that Annette Hewins had indeed bought petrol that night and wrongly said that she hadn’t. When confronted with evidence that she had bought petrol that night (leaded petrol) she accepted her error – she had been asked about that visit to Snow’s Garage months after the fire. 

Police thought she had lied deliberately, but even if they were right about that a huge problem in the case against her remained. The evidence showed that the petrol used in the arson was unleaded and there was evidence that she had bought leaded petrol. Instead of accepting that this presented serious difficulties for the prosecution case, a grossly flawed test was conducted to try to square the circle.

A forensic scientist squirted some leaded petrol onto a small section of his lab-coat. He then set it on fire and extinguished it before testing it for traces of leaded petrol, which he did not find as unsurprisingly the sample was consumed in the test. He then concluded that even if leaded petrol had been used in the arson, it would not have been detected as it would have been consumed in the fire.

First of all, it was already known that there was petrol on the carpet samples months later and the fabric and structure of the carpet bore no similarity whatsoever to the section of the scientist’s lab-coat.

It beggared belief that such a test, which was of highly questionable scientific value at best, was permitted. Nevertheless, the water had been muddied to such an extent that Clarke and Hewins were found guilty of arson with intent to endanger life and Sullivan of conspiracy to pervert the course of justice – she had allegedly given Clarke a false alibi – in 1997. Clarke and Hewins had their convictions quashed on appeal in 1999 – the case against Clarke lies on the file, although it is unlikely that she would ever face trial again, but this was not the end of the story – the science would prove to be the smoking gun of innocence.

---

[1] The xylenes can be referred to individually or as mixed-xylenes – the boiling point of the latter is 137-140° Celsius. The point for this article is that it is higher than both lead scavengers but lower than TEL.

[2] 1,2-Dichloroethane is also known as Ethylene Dichloride (EDC). It has a boiling point of 84° Celsius, which is lower than the boiling points of both toluene and the xylenes.