Charge Suppression Pistol–basically a disintegrator gun. If they’ve been around for a while, call them chasps.
Sliver Gun (I’m a bit tired of the term “needler”.)–Fires a variety of drugs or toxins embedded in slivers of soluble crystal (maybe salt or sugar). Offers interesting possible variations on “out of ammo”. The simple version would use highly compressed air. A fancier version would use charged crystals and an electric field to accelerate them. If you need something that will jam at a critical moment, an electromagnetic launcher could accelerate the crystal in a magnetic “cup”, sort of like a high-tech slingshot (this version should be louder than the other two). The sliver gun provides a nonlethal alternative, if you need one. Kindly refrain from having the drug/poison work instantly.
Synaptic Disruption Field–This is more of a restraint device than a weapon, handy for keeping prisoners from planning an escape. It causes low-level interference with synaptic impulses, disrupting higher-level brain function without killing. A helmet model could be used during prisoner transport. Of course, if you want to question someone, you’ll have to turn off the field…
If you have a specific goal in mind, it would be easier to come up with an appropriate widget.