Thanks, J_C, I appreciated your background information. They still sell the hidden key on the belt keeper ... although usually the keepers are in black nylon. Although rare, people do somehow get out of their cuffs sometimes. Here's a case I am familiar with: http://www.corrections.com/articles/3843 I don't honestly know if the inmate used a shim (especially easy, if the cuffs are not double-locked as they should be) or a hidden key. By the way, the deputy was able to use his EDC knife at one point to stab the inmate as he was attempting to get the deputy's gun. So, I have to respectfully disagree: I think these "novelties" (as Monocrom referred to them) can still be troublesome. Even if a handcuffed perpetrator cannot gain access to a hidden handcuff key, if he can keep it concealed he may be able to pass it along to some other prisoner. Although I'm now a retired LEO, too; I still think actively serving LEOs should be familiar with all such covert things that an arrestee MAY be concealing, whether handcuff key, weapon, or contraband. I know many LEOs that still conceal a handcuff key of their own in or on their uniforms in case they are incapacitated and handcuffed by the bad guy. YMMV.
Its possible to heat plastic and push it into the keyhole opening. The keyhole forms the key. A twist when its mostly hardened and its done. I worked corrections for a few years and there was always a new escape tool to be aware of. We always worked on the premise that we had 8 hours to figure out what the inmates had been working on for the last 24.
I would be highly unlikely to use such a device to escape from legitimate arrest by actual LEOs, but I might use it so I could re-cuff myself with my arms in front for greater comfort. Might nonpluss the officers when they came to get me out of the cruiser/wagon/holding area, too... OTOH, it might just annoy them, and a cranky cop is not the one I want processing me...
