Two different .30 caliber carbines were fired at lawmen during the shootout in Marion, Summit County, on Jan. 28, an FBI firearms expert testified Friday in U.S. District Court.

Richard A. Crum, a firearms and trajectory expert from FBI headquarters in Washington, said the same gun fired bullets that were recovered from the doorway of the Bates home and the garage of the Jepsen home near the Singer residence.He testified Thursday the bullets in the Jepsen garage could not have been shot from Timothy Singer's bedroom in the Singer home.

Crum said Friday a different .30 caliber carbine, a Plainfield, fired seven bullets recovered from the crime scene. Five of them were from the Bates home, including the one that killed Corrections Lt. Fred House.

One was recovered from the car parked at the Jepsen house and the other was found Wednesday in the jacket of FBI agent Donald Roberts, who was wearing a bullet-proof vest that saved his life.

During the shootout, shots slammed into the Bates and Jepsen houses west of the Singer home in the family compound.

House was killed near the Bates house. In the Jepsen home just west of it, Roberts was knocked off his chair by a slug that his bullet-proof vest stopped.

Crum showed a large diagram reconstructing trajectories of several bullets that hit the Jepsen and Bates homes, and another that was embedded in a car parked in front of the Jepsen house.

Crum who investigated the attempted assassination of President Reagan seven years ago specializes in matching bullets and cartridges with guns, and in tracing bullet paths. He said he has testified as an expert 225 times.

Visiting Marion Feb. 3 to Feb. 5, he lined up bullet holes in the houses and car in an attempt to find out where the shots were fired.

He said at least two shots went through the open door of the Bates house, passed through the house, flew out a window, and hit the Jepsen house.

In the Bates house, a back window was broken and curtains from it showed three bullet holes.

Under that theory, their target might have been officers, like House, who were silhouetted in the Bates' front doorway.

Timothy Singer was seen shortly after the shooting in his window, at the northern lean-to part of the Singer house. That was his bedroom, and rifles, live ammunition and empty cartridges were recovered there.

In earlier testimony, agents who were in the Bates house said the first shots rang out before Jonathan and Addam Swapp were aware of their presence. The brothers who were outside turned.

Jonathan knelt, pointing a gun toward the Jepsen house. Addam shouldered his weapon and was shot almost immediately by FBI agents.

Using a protractor, dowels to show the angle of bullet holes and the services of two surveyors, Crum traced back three of the shots that struck the Jepsen house and the car in front.

"We were able to determine that it would be impossible for someone in the bedroom in the Singer house to fire shots and produce the two holes in the Jepsen residence," he said. The shot into the car apparently was the result of a ricochet from the side of the Bates house, he said.

In addition, a hole in the front of the Bates house came from a shot whose trajectory he traced as a line extending to "just north of the Singer residence," missing the northwest corner of that home by nearly 6 feet.

So Timothy Singer could not have fired those shots if he was in his wheelchair at the time, as prosecutors believe.

Crum said the shots could have come from anywhere along the line of fire apparently including an area between the Bates and Singer houses. The Swapp brothers were in that vicinity at the time.

Evidence of a gunman inside the home shooting at the same time came from Agent Ronald E. Miller, a crime investigator with the Utah attorney general's office. He said branches of a fruit tree were broken off in front of the Singer home apparently struck by bullets.

Lining up these clipped branches with Timothy Singer's west window, he said there was "a direct line of sight" to the front of the Bates home.

Also Thursday, still photos and a videotape by FBI Agent Nicholas J. Repasky showed the view through Timothy Singer's window looking toward the Bates' front door, where House was killed.

From several positions at the window, especially lower ones, the door could be seen clearly. The film was made with a blue spruce back in place in front of the window, reconstructed as it was before an armored personnel carrier flattened it Jan. 28.

G. Fred Metos, lawyer for Timothy Singer, asked Repasky when the tape was made. It was shot on the afternoon of Feb. 10.

Metos pointed out that the lighting for the videotape, made in the afternoon, wasn't the same as during the shootout, which occurred in the morning hours.

"There was no attempt to duplicate lighting conditions," Repasky said.

The house faces west, so the early sunlight on the day of the shooting would have been on the house, he said. "The view (during the shooting) would have been much better" from the Singer house than shown in the videotape.

Metos seems to be trying to show that his client, Timothy Singer, could not have seen out of the window well enough to fire at the Bates house.

He asked state agent Miller how high Timothy Singer's window was above the carpet. The top of the sill was 3 feet 10 inches off the floor.

Metos then asked how high above the floor the young man's shoulder was when he sat in his wheelchair for Miller's measurements.

"From ground to shoulder is approximately 3 feet 5 inches," Miller said. From the carpet to the top of Timothy Singer's head is about 4 feet 4 inches.

Thursday's session was the first in which all defendants wore ordinary clothing, sans buckskin.

The prosecution was expected to wind up Friday afternoon. Jurors will have Monday and Tuesday free, returning to court Wednesday for the start of the defense. That is not expected to take as long as the first part of the trial.