Federal authorities are investigating alleged misconduct and civil rights violations by the Highway Patrol shown in videos in which state troopers used racial slurs, threatened to kill a suspect and — most recently — struck suspects fleeing on foot with their patrol cars.

The Criminal Section of the Department of Justice’s Civil Rights Division, the U.S. Attorney for South Carolina and the FBI are investigating the allegations, a Justice Department spokesman told The State newspaper Wednesday.

That news came as the Department of Public Safety released three more videos involving misconduct by troopers.

"I believe it’s appropriate for our office to become involved," said Kevin McDonald, acting U.S. Attorney for South Carolina. McDonald said he also referred the matter to the Justice Department’s Civil Rights Division after being made aware of the videos.

All investigations are welcome, said Department of Public Safety spokesman Sid Gaulden.

Gaulden said the handful of cases compared with the "two or three million" contacts troopers had with the public during the past four years don’t show a "pattern of systemic conduct within the Highway Patrol."

The Legislative Black Caucus supports the federal investigation into "inappropriate and unacceptable" behavior by troopers, said chairman Rep. Leon Howard, D-Richland.

"I’m sure there are (troopers) shaking in their boots," he said.

State NAACP president Lonnie Randolph said an investigation was overdue.

"It’s amazing how arrogant these individuals act ... how out of control they act with camcorders watching their every move," Randolph said.

But at least one Black Caucus member disagrees. Sen. Robert Ford, D-Charleston, said a state investigation into the Department of Public Safety will be triggered once Gov. Mark Sanford sends his candidate for Senate confirmation.

When the U.S. Attorney’s office or the Department of Justice gets involved in something like this, Ford said, “everything gets whitewashed.”

Last month, under political pressure brought on by the renomination of Public Safety Director James K. Schweitzer, the department released recordings dating back to 2004 that showed a white trooper handcuffing a black woman to the bumper of his patrol car and another white trooper yelling a racial slur and threatening to kill a fleeing black suspect.

In videos dated last year and released Wednesday by the Department of Public Safety, two other troopers are shown chasing suspects who are fleeing on foot and striking them with their vehicles. In one incident, the trooper chased the suspect through a Columbia apartment complex where children were present.

The publicizing of the first two videos resulted in Schweitzer and Highway Patrol Commander Col. Russell Roark submitting their resignations Feb. 29, after Sanford said the 12-hour suspensions the troopers received as punishment were too lenient.

In an April 2007 video, Lance Cpl. Alexander Richardson hops curbs and zips around apartment buildings in his patrol car, pursuing a man fleeing on foot through a Plowden Road apartment complex. At one point, Richardson hits the man with his bumper. Though he claimed to have accidentally hit the man, internal documents show Richardson made no attempt to brake. Unharmed, the man continues to run.

Seconds later, the chase led Richardson just feet from an occupied playground. A man and small child can be seen quickly getting out of the way of the cruiser, surprise registering on the man’s face.

The fleeing suspect eventually gave up and was arrested. Police securing the burgundy Chevrolet Caprice the man had been driving discovered two children ages 5 and 6 inside.

Richardson later said he would not have chased the car if he had known children were inside. He said he did not see the people in and around the common areas of the complex until the viewing the video.

He said he made the choice to follow the man in his cruiser "in a split second," but regretted the decision after seeing the video, documents show.

In a June 2007 video, Lance Cpl. S.C. Garren, intentionally hits a suspect who tries to cross in front of his patrol car on a narrow Greenwood street. The man managed to elude police.

A few minutes later, Garren brags to other officers that he "nailed the (expletive) out of him ..." saying he was trying to hit the man.

Sanford spokesman Joel Sawyer said the newly released videos are "disturbing." At the top of the list for the next DPS director is a "top-to-bottom look at disciplinary and promotion procedures" at the agency, he said.

"We believe very strongly in leaders’ being held accountable for the decisions and actions for those under their watch," Sawyer said.

Richardson was reprimanded for negligence in following rules, regulations, policies or procedures and ordered to take a stress management course, which he completed in August 2007, internal documents show.

A review found Garren’s actions constituted “excessive force” under the department’s Use of Force code. His bragging to officers about intentionally hitting the man could have gotten him fired, documents showed.

In December, Garren was suspended for 24 hours without pay for willful violation of rules, regulations, policy or procedure and improper conduct. He is appealing his suspension.