The white police officer who killed Michael Brown has resigned from the Ferguson Police Department, nearly four months after the confrontation that fueled protests in the St. Louis suburb and across the nation.

Darren Wilson has been on administrative leave since the Aug. 9 shooting. His resignation was announced Saturday by one of his attorneys, Neil Bruntrager. Bruntrager says the resignation is effective immediately.

A grand jury spent more than three months reviewing evidence in the case before declining in November to issue any charges against the 28-year-old Wilson. He told jurors that he feared for his life when Brown hit him and grabbed for his gun.

The U.S. Justice Department is still conducting a civil rights investigation into the shooting and a separate probe of police department practices.