What Gun Was Used in the Brian Thompson Murder?

It’s long been a joke amongst gun-totin’ Republicans in the U.S. that the mainstream media does an absolutely terrible job of reporting stories involving firearms: any Russian-looking rifle is called an AK-47, “AR” stands for “assault rifle”, the terms fully-automatic and semi-automated are often conflated, ordinary rifles become “high-powered rifles”, etc. And it’s been another bad day for journalists and commentators on both sides of the pond (including, it seems, the NYPD), as the video showing the appalling murder of UnitedHealthcare CEO Brian Thompson seems to have provoked a flurry of speculation about the particular gun used by the killer, who has been described as a “professional” and “possibly… a trained assassin”.

The excitement seems to stem not so much from the brazen and cold-blooded nature of the killing, but because the killer was clearly using a silenced (or “suppressed”) pistol – something which is very unusual outside of Hollywood films and special forces raids. It’s also evident from the video that the killer had to manually cycle the action of the gun – meaning the spent cartridge case had to be ejected and a new cartridge loaded into the chamber – after each shot. This has led many to think the particular weapon was a Brügger & Thomet VP9 (or a later version called the Station Six), which is a gun derived from the Welrod, a quiet assassins’ pistol developed for the Special Operations Executive during WWII and supposedly used by British special forces into the 2000s. But despite not being any kind of expert in this area, I’m willing to go along with the noted firearms experts Ian McCollum and the Keeper at the Royal Armouries Jonathan Ferguson in stating the gun used was definitely not a VP9 or other Welrod derivative.

There are two main problems with the VP9 claim. The first is that the manipulation needed to cycle the action of a VP9 involves a turning or twisting motion, unlike the straight-back racking of the gun’s slide that we see in the video. The second and more important problem is the very obvious puff of gas or smoke that we see coming out of the back of the gun after each shot. The Welrod (and VP9) was specifically designed not to allow gases to escape from the gun as much as possible, either from the dangerous end or from the rear of the gun – this is pretty much the whole point, since (assuming the use of subsonic ammunition) the only appreciable sounds made by a firearm are (a) the gases escaping from the muzzle and from the chamber when the action cycles, and (b) the sound made by the metal bolt as it moves back and forth between shots. At the front end, gases are trapped in the VP9 by a series of “wipes”, which are circular pieces of rubber through which the bullet travels but which close up again and trap the gas after the bullet passes. Gases at the rear are also trapped because the chamber isn’t opened as in a normal semi-automatic pistol to eject the cartridge case, but remains closed until the user manually cycles the action (which also means the bolt doesn’t make a noise when the gun fires).

The problem with the setup used by this alleged “professional” is that silencers affect the ability of a semi-automatic pistol to cycle properly, commonly because the extra weight of the silencer on the barrel (which moves as part of the action in the vast majority of pistols) means a standard recoil spring might not be able to properly chamber the next round. We see something like this in the video, where the gun is clearly “out of battery” and needs percussive maintenance. I don’t want to give advice to murderers, but testing a weapon – with or without watermelons – is considered helpful.

Despite all this, it’s easy to see why commentators have been quick to jump on the idea it was a VP9. Guns like this are fairly rare special-purpose weapons – making them sexy in a grim kind of way, and adding spice to the story. (I’m reminded of when the 7.65x21mm round used in the Annecy shootings was described as being popular with assassins – who knew?) But firearms enthusiasts love these kinds of weapons too, and can also get carried away, for instance with the modern version of the spec-ops De Lisle carbine being called the “Silent Destroyer”. Unfortunately, in this instance the firearm used was almost certainly just an ordinary semi-automatic pistol, to which the killer attached an ordinary silencer. Given the killer might well have used ordinary supersonic ammo, it’s also quite possible the gun was almost as loud as an ordinary unsilenced pistol. But that isn’t nearly so thrilling.