This spring, Maryland Rep. Anthony G. Brown introduced legislation of his own to close the boyfriend, stalker and temporary restraining order loopholes, and he has a powerful story to tell. In 2008, his cousin, Catherine Brown, a first-grade teacher, broke up with her boyfriend, Michael K. Wilson. She told her Montgomery County neighbors that she was afraid of him and asked them to call the police if they saw his car. That August, he showed up at her house, confronted her and forced her into her garage. The police arrived, but he shot and killed her before officers killed him. As lieutenant governor during the O'Malley administration, Mr. Brown successfully pushed for state-level initiatives to close those loopholes, among a host of bills to help protect and support domestic violence victims.