A slain officer's loved ones are on a mission to make sure that his killer does not get out of prison.

Officer Mathew Giglio was shot by John MacKenzie while responding to a burglary in West Hempstead back in 1975. The veteran cop endured an agonizing two months in the hospital before he eventually succumbed to his injuries.

Giglio's three children were joined by leaders of the Nassau PBA today in calling on the State Parole Board to keep Giglio's killer locked up. MacKenzie has served 36 years of a 25-to-life sentence.

He has maintained a spotless disciplinary record and earned college degrees while in prison. The 66-year-old convict has expressed profound regret for his actions. MacKenzie claims to have found God and he works to rehabilitate younger prisoners.

Giglio's daughter, Doreen Giglio Velardi, says MacKenzie's best work is clearly done behind bars. "Stay there and do God's work," Giglio Velardi said . "Don't come out, because you have an inclination to be violent and we can't afford to have another act of violence in this world."

Prison officials say MacKenzie's parole hearing is scheduled for the week of June 11.