A new government report says half of the mass attacks in the United States over the past few years started as personal, family, or workplace disputes. The attackers, the report found, were mostly men. The attackers often have a history of mental health issues, money problems or domestic violence. Their weapons of choice: guns. The report was released Wednesday by the U.S. Secret Service’s National Threat Assessment Center. The 70-page report studied 173 mass attacks carried out over a five-year period, from January 2016 to December 2020. The mass attacks happened in places such as businesses, schools and religious centers. The attacks killed a total of 513 people and injured 1,234.