Scott Lomax writes 'during their investigations the police examined the murder weapon, the Anchultz rifle, but they also examined the numerous other firearms in the building. A twelve bore shotgun revealed findings of interest to the defence, which could have assisted them at trial if they had been aware of the relevant information. Quite simply the shotgun had Sheila Caffell's fingerprints upon it.'
I am not sure if Wilkes alao mentions this and have leant the book to someone so cannot check at the moment. It would be interesting to email Scott Lomax and ask him if he saw any documentation which upholds this claim?