That's weird, it sounds like this technique is designed to just find someone guilty of something - not the perpetrator of a specific crime, just sweep up a guil

That's weird, it sounds like this technique is designed to just find someone guilty of something - not the perpetrator of a specific crime, just sweep up a guilty person. Like is the goal of an FBI agent or Policeman simply to be tricksy enough to make someone slip up, so they can sling them in jail?