A former Pittsburgh police officer on trial for vehicular homicide took the witness stand yesterday to tell how a night of Trivial Pursuit ended in the death of his best friend.

Sean Deasy, 34, was playing the board game with Joseph Walker and their wives in the early morning hours of April 21, 2004, when the two men left Mr. Deasy's Banksville apartment to go on a beer run.

On the way home, driving south on West Liberty Avenue, Mr. Deasy crashed the Ford Mustang he had owned for less than a week, killing Mr. Walker of Green Tree. Mr. Walker was co-owner of Casey's Draft House on the South Side.

After a series of delays, the nonjury trial before Common Pleas Judge Jeffrey A. Manning continued yesterday with testimony from the defense.

Mr. Deasy also faces several other charges, including involuntary manslaughter, DUI and speeding.

Police said that Mr. Deasy's car was traveling 72 mph before it spun out and crashed into a utility pole and a parked car.

A defense expert estimated the speed to be between 56 mph and 66 mph. The speed limit in that area is 35 mph.

According to police, Mr. Deasy's blood-alcohol content was determined to be between 0.11 and 0.13; the legal limit for driving is 0.08.

Yet when asked by defense attorney William H. Difenderfer if he felt intoxicated, Mr. Deasy responded, "Absolutely not."

Mr. Deasy testified that while he was driving, he noticed some teenagers standing on the edge of the sidewalk.

"I didn't know if they were going to cross the street," he said. "I didn't want to hurt them."

Mr. Deasy swerved, he said, and then struck something in the road, perhaps a pothole. The car kicked to the left and spun out of control, and Mr. Deasy testified that he remembered nothing after that.

He was taken to UPMC Mercy and treated for trauma to the head, chest and stomach.

The defense also called toxicology expert Dr. Charles Winek, who testified that a frequent drinker like Mr. Deasy, who said he drank five or six beers every day, would not be affected as much by alcohol as someone who drinks sparingly.

When Assistant District Attorney Matthew Wholey pressed Dr. Winek on the effects of a 0.08 blood-alcohol content, Judge Manning noted, "The legal limit is an arbitrary number set by the Legislature."

The trial had been scheduled to begin in 2005, but was delayed by a ruling by Judge David R. Cashman -- joined by Judge Manning -- that parts of the state's drunken driving law were unconstitutional. The resulting appeal held the case up until it resumed this year.

Judge Manning will hear closing arguments and issue a ruling Dec. 8.