For my story, they I wrote it so far is that the main character, is a cop obsessed with finding out who the villains are behind a master scheme and finding out the truth. One of members of the gang of villains went to court for his crimes, but got off for insufficient evidence. The MC, trying to find out who the leader of the gang is, figures that the leader could have likely paid for the defendant's attorney, since the defendant does not have a lot of money to afford such a high prices attorney. Now legally the police cannot get a warrant to find out who paid the lawyer. They would have to look at the lawyer's bank records, and legally the police cannot do that to any person, unless that person is suspected of crime. Of course, in this case, the lawyer is not since all he did was accept a paid service of defense. So the main character blackmails a computer hacker criminal, into hacking to the lawyer's records and email to find out who paid him. The MC finds out who did, and figures that this person could be the leader of the gang. So the MC tails that person around for days, and finally witnesses him kill another character in the story, clean up the crime scene and get away. The MC cannot stop him or arrest him for it though. Since the MC discovered the leader's identity by committing a felony, any testimony of his would be considered 'fruit of the poisonous tree', and not be admissible in court. So the MC, has to keep quiet, cause if he tells his superiors who the murderer was, and how he discovered that person's identity, he will forever be a tainted witness, and would not be of any good in his quest to bring the villains down. So he can't tell the police and has to think of something else. As the villain leaves the crime scene, I wrote it so far, that the MC perhaps cuts off the dead victim's head, and takes off with it. He will then have to wait for an opportunity to plant the head at the villain's property. Or he will have to create the opportunity himself, and then arrange for it to be found by other police. Because then the head is found on the villain's property through legal, legitimate discovery and thus, there is a piece of evidence, to link the villain to that homicide. But I was told it was implausible, cause the head would not have any of the villain's DNA or prints on, since he was careful enough to not leave any DNA or prints at the murder scene before. Therefore the villain could argue in court that the MC planted the head, and arranged for it to be found and framed him... and that would be enough to raise reasonable doubt and the villain would go free, unless the MC finds a way to get DNA and prints on the head. What do you think? Do you think that framing someone this way, will not work? The MC is kind of limited because he has to find a way to pin the murder on the villain, after all the evidence has been collected, so he has to take something from the scene before it is collected and plant it later, or he has to do something else entirely. What do you think?