STARKE, Florida — A Florida death row inmate was executed by lethal injection Tuesday for the slaying of a state wildlife officer more than 25 years ago, despite appeals from a rabbi and the Vatican for leniency.Martin Edward Grossman, 45, died at 6:17 p.m. at Florida State Prison, a spokesman for Gov. Charlie Crist said. Earlier Tuesday, the US Supreme Court refused to block the execution.Grossman was convicted of first-degree murder in the death of 26-year-old Margaret "Peggy" Park, who was shot with her own gun on Dec. 13, 1984.Grossman made a brief last statement before the execution began: "I would like to extend my heartfelt remorse to the victim's family."After expressing regret, he added, "I accept responsibility."He prayed briefly in Hebrew, then closed his eyes. He was pronounced dead 15 minutes later.Grossman was the 69th person executed in Florida since the death penalty was reinstated in the state in 1979. He was the 25th by lethal injection, the fifth executed under Crist and the first in 2010. Authorities said Grossman beat Park with a flashlight and shot her in the back of her head after she found the then-19-year-old and 17-year-old Thayne Taylor with a stolen handgun while she was patrolling a wooded area in Pinellas County. Grossman, who was on probation for a burglary, asked Park not to turn him in, but she radioed the sheriff's office.Park managed to fire a wild shot with her gun and kick Taylor in the groin, but Grossman wrestled away the gun and fired a shot into the back of Park's head.Two weeks later, authorities arrested Grossman and Taylor.Grossman was convicted in October 1985 and sentenced to death. Taylor was convicted of third-degree murder.Earlier this month, the Florida Supreme Court refused to halt the execution, rejecting claims that Grossman wasn't given a fair chance to prove his trial lawyer had been ineffective nor allowed to present certain mitigating evidence against a death sentence.As the execution date grew closer, some called for another clemency hearing for Grossman, saying he didn't deserve the death penalty for the crime."Martin has shown deep and profound remorse over the years, and is no longer the same wild, reckless person he was 26 years ago," Rabbi Menachem Katz of the Florida-based Aleph Institute said in a statement.Katz spent a few hours with Grossman on Tuesday and said he was "strong" and at peace. He said that although Grossman accepted responsibility for the crime, the inmate didn't believe he deserved the death penalty. The Vatican also asked for leniency in a letter written by Archbishop Fernando Filoni on behalf of Pope Benedict XVI.The victim's sister, Betsy, witnessed the execution, along with her 79-year-old mother, Peggy Park, and brother, Stephen Park.Park's mother said she thought Grossman's execution was long overdue. She compared his quiet death to "some of the children in Haiti who died under concrete and rubble, dark, scared, hungry. They had hardship, and I think he had it easy."Crist signed Grossman's death warrant Jan. 12. Since that time, his office has received thousands of letters, telephone calls or e-mails, according to a spokesman.