Charlotte Tillman said she and her friends were heading home to Virginia after an overnight road trip to a Wilkinsburg party when a young man they'd just met came running toward them, at a nearby gas station, shouting that two of their hosts had been shot.

James Bernard asked to borrow the 16-year-old Ms. Tillman's cell phone and yelled for someone to call 911, she testified yesterday, but then Mr. Bernard -- on trial this week for two homicides -- kept running.

"When he ran across the street we didn't believe him," she told Allegheny County Judge Kevin G. Sasinoski. The four girls left the Exxon station and continued their journey home on a drizzly Easter day, March 27, 2005.

At the house they'd just left in the 1400 block of Hill Avenue, an 18-year-old Wilkinsburg High School student named Richiena Porter had been shot once in the head while in the shower. When investigators arrived, the water was still running. She died that evening after being taken to UPMC Presbyterian.

Her roommate, 23-year-old Ricardo Hudson, was dead at the scene. The prosecution says the former coach and football player was shot multiple times in the head, "execution style," while sleeping in a bedroom.

A third roommate, LaRue Moore, testified yesterday that the defendant, Mr. Bernard, 27, of the Hill District, was friends with Ms. Porter and the two performed freestyle rap together.

Mr. Moore told the judge he was at work when he got a call about the shooting. When investigators escorted him through the crime scene, he identified an empty cigar box where he kept his loaded .25-caliber pistol, believed to be the gun used in the slayings. The weapon was never recovered.

Ms. Tillman testified that in the morning before the girls left, the defendant arrived to practice rapping with Ms. Porter. When the victim took a phone call, the defendant began freestyling about how he wanted to have sex with the girls from Virginia.

Before testimony began, Mr. Bernard signed a waiver agreeing to a nonjury trial. While reviewing the standard waiver form, the judge asked if the defendant had a mental health impairment that would prevent him from making a clear decision about forgoing his right to a jury.

Assistant Public Defender Chris Patarini said the defendant was hospitalized at UPMC's Western Psychiatric Institute & Clinic in 1999 and committed to Mayview State Hospital in June 2005 with a diagnosis of bipolar affective disorder. A forensic psychiatrist determined last month that he was fit to stand trial. Mr. Patarini acknowledged that a defense of mental incapacity would not be possible.

Testimony resumes today.