Jack Ronald Jones, convicted killer of Frostburg State College art student Stephanie Ann Roper, escaped death in Maryland's gas chamber tonight when a jury agreed after deliberating nearly 10 hours that he should be sentenced to life imprisonment.

Jones, 26, of St. Mary's County, cried softly as Circuit Judge Walter R. Haile read the panel's decision that nine mitigating factors outweighed two aggravating circumstances in the case in which Roper, a 22-year-old honor student, was kidnaped, raped repeatedly and slain. The judge imposed concurrent sentences of 20 years for kidnaping and life for rape.

With credit for time served since his arrest and with additional time off for good behavior, Jones could be eligible for parole in about 12 years.

The murder occurred during the early morning hours of April 3 after Jones and codefendant Jerry Lee Beatty, 17, who will be tried separately, happened upon Roper in her disabled car on a rural Prince George's County road. Instead of dropping her off at a friend's home as promised, they drove her to an abandoned house in St. Mary's County, where she was raped, hit over the head with a chain, shot in the head and set afire.

The jury's decision just before midnight stunned the victim's parents, who had regularly attended the proceedings, which concluded in their sixth week. "We have received a life sentence, and we're not eligible for parole after 12 years," said Roberta Roper, the victim's mother. "Society has failed our daughter and may fail others again."

Vincent Roper, a Navy captain, stood by his wife's side and said, "You can knock off a 7-Eleven and get 12 years." The judge's decision to make the sentences for the two other offenses concurrent "hit me like a ton of bricks."

"Obviously," Vincent Roper said, "the jury was swayed by emotions."

The jury said it concluded that Jones killed Roper while committing a rape and that the victim was a hostage, two of 10 aggravating circumstances enumerated by law.

The jury, however, agreed with defense contentions that Jones was unlikely to pose a continuing threat to society, that he had cooperated with police after his arrest, that his prior family history had contributed to his conduct, that he has attempted to reorder his life through religious counseling and that he has shown remorse for his crimes. The jury also agreed that Jones' use of drugs and alcohol may have contributed to his actions and that his execution would cause lifelong anguish for his immediate family.

Under Maryland's death penalty statute, a jury must be unanimous in a finding that aggravating and mitigating circumstances exist. To spare a defendant's life, the jury must decide that the mitigating factors outweigh the aggravating ones by a preponderance of the evidence.

Talking to reporters, the Ropers said the laws must be changed to provide for tougher sentences for violent crimes. "We'd like to do something positive," Vincent Roper said. "We're victims. We're hurt. There should be more victims' rights."

Before the jury began its deliberations at 1:47 this afternoon, Jones stood before the panel and said: "Ladies and gentlemen of the jury, my life is now in your hands. I'd just like to say one thing . . . If there were any way possible for me to undo the wrongs I've done I would do so; not for me, but for Stephanie Roper and her family. Thank you."