A witness testified in court yesterday that an off-duty Wilkinsburg detective barged into a house in New Kensington two years ago and pointed a gun at the four men inside.

Detective Michael J. Adams, 43, is on trial in Westmoreland County on burglary and assault charges in the June 11, 2004, incident. Mr. Adams' friend Brian Keener, 49, faces the same charges.

Prosecutors said Mr. Adams was enraged when someone damaged his BMW with a rock. A week after the incident, police said, he and Mr. Keener tracked the suspected rock-thrower to a house on Charles Avenue in New Kensington and used a baseball bat to smash a Jeep parked in the driveway.

Witness Colton Gilg testified yesterday that Mr. Adams pushed his way into the house while wielding a gun, slapped the men's faces with his badge and flashed handcuffs before placing the barrel of his service revolver in the mouth of one of the occupants, Anthony Febbraio, whom he accused of damaging his car.

Neighbor Lorna Cropcho testified that she and her husband heard cries for mercy and violent swearing coming from the usually quiet home. They confronted the strangers inside and threatened to call police.

Mrs. Cropcho identified Mr. Adams as the man who put his badge to her face and who, she said, told her "Feel free. I am the [expletive] police."

Mr. Adams was placed on leave for 30 days after the incident. He is now back at work on the Wilkinsburg force.

Martin Febbraio, whose son was in the house at the time of the incident, said Mr. Adams didn't need to get violent to get his car fixed.

"This man's a police officer. It's his job to uphold the law, not abuse it," Mr. Febbraio said. "The fact this man's still working for Wilkinsburg police says a lot to me about that department."

District Attorney John Peck said he expects to call his last witnesses today.