Michael Rosen testing the pistol out on a bunch of fake children. Or at least I think they're fake.
The pistol is a weapon used by Harold Rosen, which he used to help his accomplice Connie Rosen(Harold's wife) murder a Manchester Airport security guard, as well as a bus conductor. It is a Beretta M1951 pistol(M951R) with patridge iron sights(Adjustable) and was believed to have been stolen from a soldier of the Italian Armed Forces by a member of the Rosen family in 1951, and was passed down generation by generation because of the rarity, though most of the Rosens prefered a stronger weapon such as a bazooka, machine gun, shotgun, etc...