Definition - What does Overcharge mean?
In law, to overcharge means to charge a defendant with more offenses than the prosecution may believe that it can prove. For example, if a prosecution thinks it can prove that the defendant is guilty of breaking and entering, and robbery, but it also charges the defendant with assault and battery despite very little evidence, this would be overcharging. The reason why prosecutors sometimes do this is to put themselves in a better position for negotiations of a plea bargain
Justipedia explains Overcharge
To overcharge is to basically add on charges that are surplus to the existing charges. The goal of this is to make the defense feel that they could possibly be facing a much worse situation than they realized. It is a sort of psychological strategy that prosecutors sometimes use. The prosecutor may know that they will never be able to convict the defendant for the extra charges, but the defense may not know this. It is almost like a bluff.