The investigation, which could be announced as early as Thursday afternoon, will be conducted by the Justice Department’s civil rights division and follow a process similar to that used to investigate complaints of profiling and the use of excessive force in other police departments across the country, the officials said.

The move follows the shooting last month of Michael Brown, an 18-year-old African American, by a white Ferguson police officer who claimed he acted in self-defense. Brown, who was unarmed, was shot at least six times on the afternoon of Aug. 9.

Holder’s decision will represent the Obama administration’s most aggressive step to address the Ferguson shooting, which set off days of often-violent clashes between police and demonstrators in the streets of the St. Louis suburb.