The dea is watching a friend of mine. They think he is selling his prescription pain pills, and I really don't think he is , anyway , he has not been arrested or approached about this matter. If he was to move, is there a statue of limitation for something like this? What should he do??

Assuming it is a felony but the exact crime to be charged will very, but SOL can be from 1 year to 10 years depending on the exact crime for drugs