A man died after state troopers stunned him with a Taser when they said he became "uncooperative" after being involved in a wreck.
The State Patrol said five troopers were placed on standard administrative leave after the man's death Tuesday. A patrol spokesman would not describe what kind of "uncooperative" behavior was involved.
The state Bureau of Criminal Apprehension is leading the investigation.
"This is a traumatic event for a lot of people," superintendent Tim O'Malley said. "Someone has died, and in fairness to that person, the troopers, family members and others who may have been affected, we need to make sure that we're accurate and thorough."
The man who died was identified as Mark C. Backlund, 29, by his father, Gordon Backlund. He had been driving to the airport to pick up his parents, who were returning from a trip to Florida.
The crash occurred during the evening rush on Interstate 694, and no other vehicles were involved.
Gordon Backlund said he was told his son's heart stopped, but he added his son had no heart conditions. Autopsy results are not expected until Thursday afternoon at the earliest.
"We're looking for what really happened," Gordon Backlund told the Star Tribune of Minneapolis. "And it is just going to take time to figure this out."
State Patrol Lt. Mark Peterson didn't return telephone calls Wednesday or Thursday from The Associated Press seeking more information.
Peterson told the newspaper that State Patrol troopers began carrying Tasers about 18 months ago, mirroring their growing use among police departments nationwide.
A U.S. Justice Department study released in October said arrest-related deaths involving Tasers or other conducted-energy devices are rising, although overall numbers are low. From 2003-2005, there were 36 such deaths total, with a jump from three cases in 2003 to 24 in 2005.