The FBI announced today that the agency has launched an investigation into the shooting of unarmed 18-year-old Michael Brown, who was killed in an altercation with Ferguson, Mo. police this past weekend. The probe, Special Agent Cheryl Mimura said, will investigate "a potential civil rights violation."

Details of Saturday's shooting remain disputed: Brown was walking home from a convenience store with a friend when they were allegedly ordered to stop by the officer. Dorian Johnson, who claims to have been with Brown at the time of the shooting, contends that when the two kept walking, the officer drew his weapon.

"He (the officer) shot again and once my friend felt that shot, he turned around and put his hands in the air," Johnson told KMOV. "He started to get down and the officer still approached with his weapon drawn and fired several more shots."

The New York Times, citing police, reports that the officer who engaged Brown and Johnson was "physically assaulted" before he fired, with an alleged struggle for the officer's gun ensuing.

The St. Louis County Police Department, USA Today reports, has yet to comment on Johnson's version of events, but have announced their own narrative:

But on Sunday, Chief Jon Belmar said the incident started when a Ferguson officer encountered Brown and another male on the street near an apartment complex. One male pushed the officer into his police vehicle, Belmar said.

The men had a struggle inside the car, Belmar said, and at some point a man — it was unclear whether it was Brown — reached for the officer's weapon. One shot was fired inside the vehicle.

The fight moved outside the squad car and Brown suffered fatal gunshot wounds about 35 feet from the vehicle, Belmar said. The second person has not been arrested, and police are not sure whether he was armed.

"I understand that the public has a right to be skeptical, and I appreciate that and I would expect that the public be skeptical oftentimes of government or some forms of it," Chief Jon Belmar of the St. Louis County Police said at press conference today. "But I would also ask the public to be reasonable because it takes a long time to make sure we do this investigation the right way."

[Image via AP]