The "pow-pow-pow" of distant, fatal gunshots were heard in the Singer-Swapp trial Thursday as jurors viewed a videotape recorded during the shooting on Jan. 28 by a Summit County reserve officer.

Officer Grant J. Evans taped the shooting from a position 500 yards from the Singer compound. Jurors and some of the audience but not most of the reporters were provided with headphones that enhanced the sound of the shots. On the video screen little could be seen except a snowy foreground, distant buildings and trees, and some apparent motion of figures.A cluster of three muffled-sounding shots sounded first and were quickly followed by one louder bang, possibly from a 9 mm submachine gunfired at Addam Swapp by FBI agents, four more-slowly fired rounds and then three more shots. An additional shot is believed to have been fired, but its sound was indistinguishable from the others, according to the prosecution. The entire sequence took about 10 seconds.

Officers near Evans were commenting on the number of shots, and about four or five more were picked up by the microphones followed by the uneven sounds of sirens. When the shooting began the videotape picture lurched.

One of the officers apparently noticed Addam Swapp as he was moving near the trees after he was wounded and commented, "So he spotted the guys in the green house, eh?"

The Bates' home where FBI agents and state corrections officers were hiding was called the green house. It was there that Lt. Fred House was shot to death.

One of those in the house, FBI Agent Donald C. Roberts, was knocked off his chair during the shootout at the Singer compound. He thought he was hit by gunfire, but he turned out to be uninjured.

Not until Wednesday did Roberts find out a bullet had penetrated his jacket within a few inches of his heart.

Roberts' testimony was the biggest surprise so far in the Singer-Swapp trial.

He said that on the morning of Jan. 28, the day of the shootout that killed corrections House, he was stationed in a staging area to the west of the building occupied by House and other agents. Roberts, Salt Lake City, was in the kitchen of the Jepsen home, along with other FBI agents.

Peering through a window toward the Singer log house, he saw Addam and Jonathan Swapp head toward the goat pen, the event that precipitated the shooting. A state corrections officer asked for water for his police dog, and House got up to get some from the sink and returned to his post.

"I heard a loud explosion, gunshot, immediately in front of my face at the wall," he said. The shot blasted out plaster just under the window.

A cloud of powdery white material flew at his face and "I felt a sharp pain." He fell off his chair, crying, "I'm hit, I'm hit."

Another agent jumped on top of Roberts and searched for a wound. But he found none. His outer flight jacket had a small hole in the left chest, and the bullet-proof vest under it had a matching hole in it.

These holes were close to the heart, although a little to the left of it.

When the bulletproof vest was examined with a metal detector a week later, nothing showed up. The assumption was that Roberts had been hit with a fragment of plaster or some other material from the house, or that it was such a tiny fragment of a bullet that it was undetectable.

On Wednesday, when he came to court, the outer jacket was put through an X-ray machine operated by security officers on the first floor of the courthouse. Through this machine officers run attache cases, handbags and anything else that could conceal a weapon.

What did the machine reveal?

It "found what appeared to be a bullet in the jacket," he said.

There in the courthouse, the jacket was cut open with a pocket knife. "And a bullet dropped out," Roberts said.

It had apparently gone through the wall of the Jepsen home, penetrated the jacket, gone into the vest, bounced back out and re-entered the jacket. The slug fell into the lining and was undetected until Wednesday.

Roberts displayed it to the jury, holding up a copper-jacketed bullet that looked larger than .22 caliber. It was to be tested overnight Wednesday by the FBI crime lab to determine which gun fired it.