[H] "Hold still, we're going to try this again."
[galactic volunteer] "It won't knock me out like last time?"
[H] "Nope, bugs are worked out, we tested on other humans first for a reason after all, that knock-out was accidental, sorry about that."
[galactic volunteer] "Alright, I'm ready."
The human throws the small metal disk which adheres to the galactic and, suddenly, they can't move. They can breathe, see, hear, they are not being hurt, but they can't, otherwise, move.
[galactic] "Well... it works, take it off now please."
[human] "Thank you very much for your help, I'm grateful." They remove the disk and transfer time to their volunteer's account before heading straight to medical
[galactic] "Why did you make that?"
[Human] "The more we go after bad guys, the more people end up dying in the fight. The more we can stop bad guys without killing, the happier I'll be." -- DaniAndShali
All high-octane policing has one significant problem - collateral damage. Even with stunner fire, a miss can create problems. Worse, many stunners need calibration to be sure that the target species is safely knocked out, without harming any others. Since many offenders are Deathworlders, this means that any Havenworlders caught in the crossfire could die. They needed a better way that wasn't controlled exclusively by a keen eye and a steady hand.
Which was the key to the body lock disk. A specific charge, some micro-scanners, and a very specific program involving species specific neurology and nanomachines to seek out and disrupt certain key areas. Upon contact, the disk released a series of seeker drones that spun nano-wires into the prospective victim's nervous system. It would scan the one struck, and render them immobile without also ceasing autonomic functions.
Those struck by it would be stopped, without it being terminal. From Havenworlder to Deathworlder, any fleeing miscreant would not be able to escape justice. Of course, they tested it from Deathworlder to Havenworlder, in that specific order, with Mediks on standby in case anything went wrong. It didn't.