My sister just recieved a check for $5,000. It is from a man in Los Angeles, drawn a bank in LA. It came in an airmail envelope mailed from somewhere in England with no return address, in the memo section of the check it say "service". I think it's some kind of money laundering scam. I think when they see the check cleared they contact you and say you recieved the check by mistake and need to return the money. Do you think I'm right and she should give it to the police?