Four young men were playing video games in North Braddock when one opened fire with a real gun, killing two of his friends, according to the fourth player, who testified yesterday in Allegheny County Common Pleas Court. The shooter then gave him a choice: He could stay and meet the same fate, or go.

Marlin Sanders testified that he fled the murder scene with the assailant, Erskine Smith, who is on trial in the deaths of Jonathan Hutson, 19, and Daniel Underwood, 17. Mr. Sanders later told police the shooting was Mr. Smith's doing.

Mr. Smith, 20, also faces a gun charge and two counts of robbery for stealing the PlayStation 2 console and taking cash from Mr. Hutson's pockets.

In testimony that was contradictory and confusing, Mr. Sanders said he skipped school Nov. 9, 2005, and went in the early morning to Mr. Hutson's house to offer protection while his friend handled several drug deals in and around his home.

Later that day, the witness said, the two other friends arrived at the house, although he wavered on the order of their arrival. Mr. Sanders told jurors he stayed at Mr. Hutson's house all day, but then explained that either before or after the friends arrived he made a quick trip to the store to buy some "blunts" -- cigars they could use to smoke marijuana.

At one point, Mr. Smith and Mr. Hutson were bragging about who had a bigger gun, but neither was angry and both put their weapons away, the witness said. The foursome began playing Madden NFL "to see who was better." Then they moved the console from the living room to a back bedroom.

"We were all safe. Nobody had a problem," Mr. Sanders testified. He said they had all smoked marijuana.

The two victims were taking a turn facing off at the controls when, without uttering a word, Mr. Smith shot the host from behind with a .22-caliber pistol, Mr. Sanders said. He said he heard pops and saw flashes and his right ear was ringing from the gunfire.

Mr. Hutson had four gunshot wounds to the back of the head, four stab wounds to the throat and one to the cheek. A forensic pathologist found no defensive wounds, indicating that Mr. Hutson had no opportunity to try to fight off the attack.

Mr. Sanders testified he didn't know who stabbed Mr. Hutson. The bleeding pattern indicated that the stab wounds were inflicted last, according to the pathologist.

The second victim attempted to escape through the living room. The defendant shot him as he pleaded for mercy, Mr. Sanders testified.

Mr. Underwood had two bullet wounds to the head. He also did not have defensive wounds. The forensic expert concluded, based on gunpowder residue, that the muzzle of the gun was one to two feet from his head when the bullets were fired.

Toxicology tests found no evidence that either victim had marijuana or alcohol in his system.

When Mr. Smith returned to the back bedroom, Mr. Sanders recalled, "he just looked out of his mind. He didn't point [the gun] at me. He said, 'Either you're gonna leave now or end up laying here.' "

Mr. Sanders split up from the defendant and was picked up by police for questioning.

Prosecutor Ilan Zur said in an opening statement that after the homicides, the defendant gave county police a statement confessing that he shot Mr. Hutson but saying he then blacked out. Jeans recovered from the home of Mr. Smith's girlfriend had stains that were positive matches for both victims' blood, Mr. Zur said.

Earlier, Mr. Hutson's mother, Tracey Pollard, testified about discovering the two bodies when she returned home from work.

She told the jury she had spoken with her son on the phone four times that day. The door to her house was chained shut, she said, but when she saw a body on the floor, she broke the chain. Mr. Underwood was lying on his side near the front entrance. Soon after, she learned her son was lying dead in his bedroom.

Family members came and went from the courtroom in tears yesterday while Mr. Zur reviewed photographs of the slain men with the pathologist.

The jury also heard from the defendant's girlfriend, who said he seemed normal when she picked him up at a friend's house on the night of the homicides.

Mr. Zur asked if she thought Mr. Smith would tell her if he'd just shot a friend twice, and put four bullets into another friend's head and stabbed him in the throat. She said, "No, probably not."

Testimony resumes today before Judge Donald E. Machen.