Can I take legal action against an ex who stole money from my account?

You may contact the local police department -- or sheriff's office -- where the offenses occurred and file a complaint.  (Whether you contact the police or sheriff's office depends on whether the offense happened within city/town limits or in the county.)   More than likely he will be charged and a warrant for his arrest will be issued.  Since he's in Pennsylvania, you will need to let law enforcement know that.  With regard to the unauthorized use of your ATM card/s, the bank and law enforcement will probably want to know how he could have used it unless you gave him the password.  Inmy experience, banks usually are unwilling to make good on any unauthorized/fraudulent transactions unless the account holder is willing to press charges against the wrongdoer.  Even then the bank may not want to make good on what was fraudulently taken from your account unless the bank thinks it may have been  somewhat at fault for allowing the transaction/s to go through.