ST. PAUL (AP) - Prosecutors have dropped charges against a St. Paul man accused of pointing an assault rifle at his teenage daughter because of her grades in school.

The 51-year-old man had been charged with two counts of making terroristic threats, a felony. He was accused of pointing the rifle at his 15-year-old daughter and his wife during an argument at their home in January 2013.

A spokesman for the Ramsey County Attorney's office says the alleged victims refused to cooperate, making it nearly impossible to prove the case.

The complaint says the man had recently bought the AK-47 because he feared the gun would be banned. He allegedly had threatened his daughter with it because she was getting two B's in school rather than straight A's.