Is it true most psycho killers are actually government patsies brainwashed into believing they did their crime?

the police grab them, they are brainwashed, then they admit it. they were made crazy over time by the government secretly giving them drugs, which make them more susceptible to suggestion and brainwashing. someone told me this awhile ago when i was serving in iraq, i think they were a mercenary or from some other country. it makes sense, except for the witnesses. perhaps they are brainwashed another way? maybe they are in on it too? is this believable?