Manipulating a victim in that way, under the color of authority, would be a capital crime in a country run by me.
That is pretty much how the whole plea deal concept works. The original intent may gave been good, to solve crimes easier by disrupting criminal networks with distrust, but it was quickly abused and led to more, not less corruption by rewarding suspects for lying and rewarding prosecutors for confessions whether truthful or not. When you lie to get suspects to confess, how are you any better than the criminal? You aren’t rewarded for honesty, you are rewarded for lying, no matter which side of the law you are on. And now, after decades of legally authorized deceit, the crime problem has gotten much worse and more depraved than ever, and people no longer believe the authorities are honest, but assume them to be liars, too.