Rep. Bill Janklow (search) told investigators he was accelerating to pass another vehicle when he rammed his car into a motorcyclist and killed him, according to a new document filed in his second-degree manslaughter case.

The South Dakota (search) Republican told two state troopers and a sheriff's deputy that he "gunned" his Cadillac to get around another vehicle coming toward him at an intersection.

"I was slowing up for that stop sign and I just raced around it. I gunned around him," the document said, quoting Janklow.

It was unclear whether the other vehicle was on the same road as Janklow or on an intersecting road.

The statement came in an affidavit filed by the prosecution in an attempt to get Janklow's past speeding tickets entered into evidence. But Judge Rodney Steele (search) affirmed an earlier ruling not to allow Janklow's driving record into his trial.

However, Steele said he may allow testimony on two other accidents in which Janklow reported seeing a vehicle that nobody else did -- if the defense brings up the so-called phantom vehicles.

The prosecution filing also quoted Janklow's chief of staff, Chris Braendlin, who was in the car, as saying Janklow slowed down before the Aug. 16 collision with motorcyclist Randy Scott of Hardwick, Minn.

"And I do recall seeing a motorcycle going across the intersection and then something came by us," the affidavit quoted Braendlin as saying. "But (Janklow) was slowing down. I do remember that. He was slowing down."

The motorcycle referred to by Braendlin is that of Scott's friend, Terry Johnson, who went through the intersection a few seconds before Scott.

Janklow, a former four-term governor who was elected to the U.S. House in 2002, is charged with going 71 mph in a 55-mph-zone, not stopping at a stop sign, reckless driving and second-degree manslaughter, a felony.

That count carries a maximum punishment of 10 years in prison and a $10,000 fine. His trial starts Dec. 1.

A misdemeanor conviction would not affect Janklow's ability to serve in Congress. But the House ethics committee would automatically investigate Janklow if he is convicted of a felony.

In two previous accidents, Janklow told police he was trying to avoid another car, according to court documents. One of those happened Dec. 27, 1993, when Janklow rear-ended a vehicle while traffic slowed to make way for two police cars.

In the other, on Nov. 24, 1993, Janklow collided with a Sioux Falls city bus after pulling forward "to avoid being struck by a phantom vehicle," according to the accident report.