An Allegheny County jury deadlocked yesterday on a possible death sentence for the man convicted of killing a Pennsylvania state trooper during a 2005 traffic stop in Carnegie.

The deadlock means the judge must sentence Leslie D. Mollett, 32, to life in prison without the possibility of parole for the murder of Cpl. Joseph R. Pokorny.

Public defender Lisa G. Middleman said Mr. Mollett "was obviously very relieved and said, 'Thank you.' "

"I was just very gratified that there was at least one person out of a death-qualified jury that was able to look past the very heartbreaking victim impact testimony and to see that the taking of another human life would not be of any use in commemorating Joe Pokorny's life," Ms. Middleman said.

The jurors, who were sequestered for two nights, left with suitcases and duffel bags through a guarded exit. They declined to comment about the eight hours they spent deliberating and requested that sheriff's deputies escort them from the building.

The slain trooper's sister, Laura Hill, spoke on behalf of her parents and brother, who sat through nearly all the testimony in the monthlong trial, and on behalf of the trooper's teenage children, who attended the penalty phase.

"This is a bittersweet time for our family. It's been a long two years and it's been a grueling past month. We are pleased with the guilt phase of the verdict and now it's time for us to heal and celebrate Joe's life," Ms. Hill said.

State police Maj. Robert Lizik, representing police commissioner Col. Jeffrey B. Miller, said, "The jury did an exceptional job throughout this whole trial. A trial of this length is very draining to anyone involved. We felt the death penalty was appropriate but we accept the jury's decision."

Deputy District Attorney Mark V. Tranquilli said, "I just have a debt of gratitude to the [jury] that they were willing to make an attempt to make a decision." He would not say how the jury split on the vote.

"The last thing I want to say is that Joe Pokorny is in a better place than Leslie Mollett's going to be for the rest of his life. I think some place right now -- his family would agree with me -- Joe's probably got a smile on his face. He got his measure of justice."

Uniformed state troopers stood at parade rest outside the district attorney's office when Cpl. Pokorny's parents emerged, his mother in a wheelchair recovering from a leg injury. Mr. Tranquilli bent down to Florence Pokorny. She smiled, took his hand and kissed him on the cheek.

"You did a great job," she told the prosecutor.

Shartaya Mollett, who attended most of the trial and testified in the penalty phase, said, "I feel very good. I'm just happy my uncle is not going to die."

Mr. Mollett's mother, Brenda Banks, told a crowd of relatives the decision was in God's hands.

Two days prior, she ran from the courtroom when the jury found her son guilty of first-degree murder in the death of the 22-year veteran officer. The jury also convicted him of resisting arrest, disarming the trooper, stealing his trooper's state-issue Beretta firearm, fleeing, avoiding apprehension and two gun offenses.

The first-degree murder verdict carried a possible death sentence because the victim was an on-duty policeman.

Jurors heard a full day of testimony Thursday from the families of Cpl. Pokorny and Mr. Mollett before Common Pleas Judge Lawrence J. O'Toole instructed them to weigh one aggravating factor, that the victim was a police officer, against the mitigating factor of the defendant's character, record and background.

Cpl. Pokorny's family told jurors about the ripple effect his death has had on their family. They said he was an outstanding sportsman, coach and mentor.

Mr. Mollett's mother, sister, brother, cousin, niece and two of his three children talked about him as a caring man who coached sports, cared for ailing relatives and inspired young people to make good choices.

After jurors confirmed the deadlock one-by-one, the judge set Mr. Mollett's sentencing for Dec. 20.