Authorites have said Officer Taylor Krauss mistook Officer Jacai Colson for an armed threat. The undercover narcotics officer, an African-American, was wearing plainclothes when he responded to the March attack.
Prince George's County State's Attorney Angela Alsobrooks said Colson's family is "disappointed" and wants people held accountable.
Authorities say 22-year-old Michael Ford's brothers drove him to the police station and recorded videos of him firing at buildings and vehicles. Ford faces 55 counts, including second-degree murder in Colson's death. He and his brothers, 21-year-old Malik and 18-year-old Elijah, also are charged with attempted murder.