COLUMBIA, S.C. (AP) — A federal investigation was launched into the South Carolina Highway Patrol after dashboard camera videos showed a trooper using a racial slur and two others ramming their cruisers into fleeing suspects, a prosecutor said Thursday.

"I've reviewed some of the videos, and based on that review, felt that it was appropriate to have our office involved," said Kevin McDonald, acting U.S. attorney for South Carolina.

McDonald wouldn't say whether indictments could come from the investigation, which was first reported Thursday by The State newspaper of Columbia.

Highway Patrol Col. Russell Roark and his boss, Public Safety Director James Schweitzer, resigned last month after a tape surfaced showing a trooper using a racial slur in 2004.

"You better run," then-Lance Cpl. Daniel C. Campbell said to a suspect, using a derogatory term for blacks, "because I'm fixin' to kill you."

Campbell was reprimanded, suspended and ordered to undergo anger and diversity training, but Gov. Mark Sanford said Roark and Schweitzer should have fired him.

This week, the Highway Patrol released two more videos, both from 2007, showing troopers using their cars to ram suspects.

In one of those tapes, Lance Cpl. Steven C. Garren drives after a black man on foot, striking him when he crosses in front of Garren's cruiser. The man is sent flying into high grass on the roadside.

"Yeah, I hit him. I was trying to hit him," Garren, who is white, can be heard telling another trooper. Garren received a three-day suspension, which he has appealed.

Another video shows Lance Cpl. Alexander Richardson chasing a running man at an apartment complex, driving between buildings and on sidewalks, passing onlookers, including a small child. The suspect appeared to be hit at a slower speed and kept on running. Richardson was reprimanded and completed a stress management course, disciplinary records show.

Sid Gaulden, a spokesman for the Department of Public Safety, said the department welcomes the investigation and believed it would show there is no systemic pattern of misconduct. "We saw problems and took action to correct those problems," he said.