My friend's ex boyfriend is terrorizing her and makes threats to me. What can I do?

Her boyfriend just cant seem to get over it. He texts her constantly threatening her and accusing her of being a . He stalks her house, leaves messages on our voicemail at work calling us names and whatnot; but he never addresses the fact that he vandalized her house and stole her car, broke into her house, threatened my life, and hit her car as we were driving and mentally terrorized her for the past few weeks. Now he wants to forget about it as just a "misunderstanding". What can we do?