David Boutflour, nor any of the other relatives, 'did not even know' that Ralph Bamber had purchased the .22 semi - automatic rifle, until 'after they recovered one of the silencers from the scene on the 10th August 1985'. Nobody told them which weapon had been used to shoot the victims with, until much later. In fact, the relatives were led to believe originally that Sheila had killed everyone with use of a shotgun, including herself...
Jeremy couldn't have told them, because even he did not know, nor was he told by cops about 'which' gun had fired any of the shots, but the closest cops got to telling anyone about the identity of the type of weapon that may have been used, was when DCI 'Taff' Jones, and DS 'Stan' Jones went to see Jeremy at his cottage on the afternoon of the 9th August 1985, and questioned him about (a) was the telescopic site fitted to the rifle on the evening just prior to the shootings, (b) was the silencer fitted to that rifle, at that stage, (c) how many rounds were already in that gun when he first took possession of it, (d) how many more rounds did he load into the ammunition magazine, if at all, and (e) where did he get any additional ammunition from?
At the end of these questions, cops then asked him where he thought five additional bullets which they knew had been fired during the killings had originated from, because they said there was still 30 full rounds with the ammunition box he had left on the kitchen side before going home?