Theodore Simmons was convicted Thursday of murdering the Rev. A. Joseph Bissonette and Monsignor David P. Herlihy during robberies two weeks apart last year in their rectories.
Prosecutors said they would ask for the maximum prison term of 50 years to life for Simmons, 19, of Wyoming Avenue and his codefendant, Milton Jones, 18, of Ivy Street, who was convicted in a separate trial earlier this year.
"These were two of the most heinous crimes that have ever been committed in this community," said District Attorney Kevin M. Dillon.
"There was no justification for the murders of two priests who had devoted their lives to helping others, and there should be no mercy shown."
Simmons was convicted of two counts of murder in the monsignor's slaying, with the jury finding that he had intentionally killed him and that he had killed him during a robbery.
But he was convicted of just one count of murder in the case of Father Bissonette, with the jury finding that he had killed him during the course of the robbery but had killed him unintentionally.
Prosecutors explained that the jury apparently concluded that Simmons had not intended to kill Father Bissonette during the robbery but had only killed him as an afterthought.
As the jury announced its first finding shortly after 5 p.m. -- innocent of intentional murder in the death of Father Bissonette -- Simmons jumped back in his chair and smiled.
But his demeanor quickly changed as the jury foreman announced a steady stream of guilty verdicts on the three other murder counts, two robbery counts and three weapons-possession counts.
Simmons and his family refused to discuss the verdict as he was being taken back to the Erie County Holding Center.
Members of the victims' families praised the jury's decision, which followed 11 hours of deliberations that started Wednesday afternoon.
John Herlihy and Catherine Gallivan, brother and sister of the slain monsignor, said they were elated.
"I think justice has been done," Mrs. Gallivan said.
Ann Bissonette, sister-in-law of Father Bissonette, said both victims' families are relieved that both trials are over, but she said the killings continue to haunt the families.
"There's going to be a shadow over us for a long time, but the message of the jury was clear," she said.
Jury foreman Larry Bolden called the verdict "fair and just," but neither Bolden nor other members of the jury would say more about their deliberations.
State Supreme Court Justice Frederick M. Marshall set sentencing for Oct. 31, the same day that Jones is to be sentenced.
Each faces a minimum mandatory prison term of 15 years to life and a maximum possible term of 50 years to life. They would not be eligible for parole until they serve the minimum term Marshall sets.
George R. Blair and J. Glenn Davis, Simmons' court-assigned attorneys, said they would appeal the verdict.
Father Bissonette, 55, pastor of St. Bartholomew's Church on Grider Street, was slain Feb. 24, 1987, during a $200 robbery in the rectory.
Monsignor Herlihy, 74, was slain March 7, 1987, during a $700 robbery in the rectory of St. Matthew's Church on Wyoming Avenue. The rectories are less than a mile apart.
Both priests were bound, gagged and stabbed repeatedly in the heart as they sat tied to chairs.
Father Bissonette was stabbed 10 times and Monsignor Herlihy 20 times. The knife used in both attacks was never found.
Both victims also were bludgeoned, Father Bissonette with a can of chow mein and the monsignor with a glass jar.
Simmons was acquitted of using the chow mein can as a weapon to bludgeon Father Bissonette but was convicted of using a knife to stab both victims and a glass jar to bludgeon the monsignor.
Simmons' fingerprint was found on the cash box inside the locked safe at St. Matthew's.
Jones told police in March 1987 that he had staged the attacks with Simmons because he wanted money to finance drug-dealing and to provide for a son born out of wedlock.
He was convicted Jan. 29 of intentional murder and felony murder in both slayings after a jury deliberated for two hours after a two-week trial.
First Deputy District Attorney Frank J. Clark, the chief prosecutor in the Simmons trial, said the verdict showed that the jury rejected Simmons' contentions that he was an innocent and unwilling participant in murders committed by Jones.
Although the defense argued that Simmons participated in the killings under duress as a result of the threat of physical injury from Jones, "the jury obviously rejected that defense," Clark said.
Simmons told police that the muscular Jones forced him to be an accomplice by threatening to hurt him and his elderly adoptive mother, but the jury during its deliberations had testimony read back about Simmons' reputation as a panhandler and a series of late-night visits that Simmons paid to St. Matthew's about the time of the murders.
During his instructions to the jury, the judge said that to accept Simmons contention that he was a victim of duress, they had to be convinced that there was no way for him to have resisted Jones.
Marshall stressed that the jury would not have to accept Simmons' contentions if it were convinced that neither he nor his mother were in immediate danger of physical harm.
"Place yourselves in the shoes of the defendant," the judge told the jury, and decide whether "a person of reasonable firmness" could have resisted the threats Simmons said Jones had made.
Simmons, like Jones, did not testify during his trial.