Derek Bentley Case - To Encourage The Others

In his 1971 book To Encourage the Others, David Yallop documented Bentley's mental deficiencies, inconsistencies in the police and forensic evidence and the conduct of the trial. He proposed the theory that Miles was actually killed by a bullet from a gun other than Craig's sawn-off .455 revolver. Yallop drew this conclusion from an interview in March 1971 with Dr. David Haler, the pathologist who carried out the autopsy on Miles, who Yallop reports estimated the head wound was inflicted by a bullet of between .32 and .38 calibre fired from between six to nine feet away. Craig had been firing from a distance of just under 40 feet and had used a variety of under-sized .41, and .45 calibre rounds in his revolver; Yallop asserted it would have been impossible for him to use a bullet of .38 or smaller calibre. Haler did not offer in his trial evidence any estimate of the size of the bullet that had killed Miles. In July 1970, during an interview with Yallop, Craig accepted that the bullet that killed Miles came from his gun, but maintained that all of his shots were fired over the rear garden of a house adjacent to the warehouse, approximately 20 degrees to the right of Miles's location from where Craig had been firing.

The standard Metropolitan Police pistol at the time was the .32 Webley automatic, a number of which were issued on the night. In his book The Scientific Investigation of Crime, the prosecution's ballistics expert Lewis Nickolls stated that he recovered four bullets from the roof, two of .45, one of .41 and one of .32 calibre. The last was not entered as an exhibit in the trial, nor mentioned in Nickolls' evidence to the court.

When Yallop telephoned Haler the day after the initial interview, he reportedly confirmed his estimate of the bullet size. Shortly before the publication of Yallop's book, Haler was provided with a transcript of the interview, and Yallop says Haler again confirmed as accurate. After the subsequent broadcast of the BBC Play for Today adaptation of To Encourage the Others, directed by Alan Clarke and starring Charles Bolton, Haler sought to deny that he had given any specific estimate of the size of the bullet that killed Miles beyond being "of large calibre".