An NYPD deputy commissioner — the brother of an officer assassinated in 1988 — said Friday his family’s mission is to make sure his sibling’s killers “never see the light of day.”

Friday marked the third time that Lawrence Byrne, whose brother was killed guarding a witness in an ongoing drug case, delivered an impact statement at the parole hearing for the four men convicted of the Queens slaying.

“Five days after his 22nd birthday my brother was shot five times in the head, and these assassins laughed and bragged about how they killed a cop in Queens,” said Byrne, 56, the NYPD deputy commissioner for legal matters, outside the parole board office in Manhattan.

“That’s how we caught them days later.”

Edward Byrne was 22, a rookie cop living in Massapequa, when he was killed guarding the home of a man known only as “Arjune.”

The man was a witness in an ongoing drug case and his home had been previously firebombed to discourage him from testifying, according to a news release from the police union.

advertisement | advertise on newsday

The four assassins — David McClary, Scott Cobb, Todd Scott and Philip Copeland — shared $8,000 for the murder and later bragged to others about their crime.

They later testified against drug kingpin Howard “Pappy” Mason, who was convicted of ordering Byrne’s killing from jail and is serving a mandatory life sentence in federal prison.

Each of the four has served 25 years for the killing and is eligible for parole every two years; each has been denied previously. The board said it expected to decide on parole some time in November or December.

Byrne told reporters outside the parole office that his message to the four is “You will spend your life in prison and you will never see the light of day.”

He vowed his three sons would keep up with the family mission to appear before the parole board when he was gone.

Officer Byrne was shot in the head as he sat alone in a patrol car outside the house on 107th Avenue in South Jamaica on Feb. 26, 1988.

Later, the home that Byrne was guarding was razed by the city and turned into a park in his honor.

With Gary Dymski