Great observation:

In real life, however, if several people are involved in a crime and one of them offers to talk, detectives must make a judgment call. If they charge everyone with the maximum, everyone will lawyer up. So detectives work to “flip” the accomplice who seems less culpable. This horse-trading strikes many outsiders as ethically questionable, and criminals consider it betrayal (hence the saying “snitches get stitches”). Yet the law allows it so long as the police do not knowingly solicit perjury. Without deals like this, it would be impossible to solve cases in which the only (or best) eyewitnesses to a crime are involved in it. And those happen every day.