For my story, it's a thriller that has the structure we've read before where a cop will go out on his own to prove his whole department and the whole system wrong on a case, even though he is taken off the assignment. This is where it gets tricky in the writing cause he has no warrants or no wire tap orders to get any evidence, and has no probable cause either to seize and search any evidence. I have been doing research on how to possibly get around the fourth amendment, for the main character to win, but have not found much luck as the law is pretty airtight it seems. However, I found out that a judge is technically allowed to admit evidence, if it is mailed to the police anonymously, as long as the physical evidence is solid enough. So let's say that the MC has taken solid evidence and has placed it all in a package to be mailed to the police. The villains who he has evidence on have caught up to him, and head to mail to take back the evidence. The MC calls the police and tells them he has been following the suspects to see what leads he could get and he has caught them trying to rob a mail box. As back up is coming the MC would try to stop them and arrest them. However, would this fly, legally in court? Cause the MC is pursuing them, when he was taken off the case and specifically told not to, after they have been cleared. Then when back up arrives, the villains will have to explain themselves or they can remain silent. But the police are going to investigate and they will find out that in that mail box, there is a package in the mail box with the evidence that is needed to convict the gang. But will a judge accept this arrest and evidence if it looks this suspicious? Basically the cop was taken off the case and was known to have a grudge against the gang, and the police were currently out looking for him cause they knew he was after the gang and was 'up to something' as the expression goes. Then when the police are looking for him and cannot find him, he all of a sudden calls them saying that the he is tailing the gang to see what leads he could come up with, and that they are robbing a mail box and requests back up to intercept it. And the mail box has a package in that they were trying to steal back which so happens to contain the evidence. Now I read that a court can accept evidence that is mailed in anonymously, but would they accept it, if the one cop who has a grudge against the gang, and has been AWOL for a while and was tailing the gang at the time, that they gang was trying to steal back the mailed in evidence? Would this be plausible to work at all legally and get around the fourth amendment? The one possible problem is, is that the villains can say that the MC took the evidence from them and arranged for it to be mailed in himself. But it depends on how good of a defense this is. 1. In real life, I'm sure crooks say that the cops planted evidence a lot of the time, but that doesn't mean that the police would let them go. If this were the case it would be the standard excuse, defendants would use to get off. 2. If the villains argue that the evidence was stolen and put in the mail, they would be admitted that the evidence was in their possession prior, and thus incriminating themselves. But if you are arguing that the cop obtained the evidence illegally, and arranged to mail it in, can your words be used against you, since you are defending yourself against unlawful seizure and it would be fruit of the poisonous tree, if that were the case? Does anyone have knowledge of that? Thank you very much for the input. I really appreciate it.