WASHINGTON — The police officer who fatally shot an unarmed 18-year-old in a St. Louis suburb last summer has told investigators that he was pinned in his vehicle and in fear for his life as they struggled over his gun, The New York Times reported.

Ferguson, Missouri, police officer Darren Wilson has told authorities that Michael Brown reached for the gun during a scuffle, the Times reported in a story posted on its website Friday night. The officer’s account to authorities did not explain why he fired at Brown multiple times after emerging from his vehicle, according to the newspaper.

The Times reported that the account of Wilson’s version of events came from government officials briefed on the federal civil rights investigation into the Aug. 9 shooting that sparked racial unrest and weeks of protests, some of which turned violent. Wilson is white and Brown black.

Wilson confronted Brown and a friend while they were walking back to Brown’s home from a convenience store. After the shooting, Brown died at the scene. Some witnesses have told authorities and news media that Brown had his hands raised when Wilson approached with his weapon and fired repeatedly. An independent autopsy commissioned by the family says that Brown was shot at least six times, including twice in the head.

The Times reported that Wilson has told investigators that he was trying to leave his SUV when Brown pushed him back in and that once inside the vehicle the two began to fight. Wilson told authorities that Brown punched and scratched him repeatedly, leaving swelling on his face and cuts on his neck, the Times reported.