A woman serving a life sentence in a celebrated murder case from Little Rock died Monday morning after apparently suffering a heart attack in prison. Mary Lee Orsini was 55. Orsini was convicted in 1982 in the contract killing of Alice McArthur, her former lawyer`s wife. McArthur was shot July second, 1982 -- two months after an unsuccessful car bombing attempt. Orsini also had been convicted of killing Ron Orsini, her third husband, but the state Supreme Court threw out the conviction on a technicality and prosecutors decided not to retry her because she was serving life without parole for McArthur`s death. Alice McArthur`s husband William said in an interview today that a motive was never established in his wife`s killing and that he never figured out Orsini. ------ At the time Alice McArthur died, her husband was representing Orsini as police investigated her in the March 1981 death of her third husband. Larry McClendon and Eugene "Yankee" Hall also were convicted of murdering Alice McArthur. They were arrested just days after her death, but Hall told prosecutors that Mary Lee Orsini had orchestrated it. Mary Lee Orsini later made audio tapes of a supposedly anonymous phone call claiming McClendon and Hall had acted on their own accord, but police recognized the caller`s voice as that of her friend, local real estate agent Larry Burge. Burge kept notes he said Mary Lee Orsini had given him to read over the phone, and they became the evidence used in court to corroborate Hall`s testimony against Orsini. Dina Tyler, the prison system spokeswoman, said Orsini had no known heart problems and had never complained of feeling ill until her overnight complaints. She worked a desk job at the prison, counseling other inmates.