Lawrence Byrne is fighting to keep his brother's killers behind bars. 

David McClary, Scott Cob, Todd Scott and Phillip Copeland assassinated Edward Byrne back in 1988 as the rookie police officer on the orders of a drug king as he was guarding the home of a witness. The murder shocked the city, the nation and destroyed Byrne's family.

“My 81-year-old mother grieves over the irreplaceable loss of her son. My dad, a retired NYPD officer who served for 22 years passed away in 2015 but part of him left us on February 26, 1988,” Former NYPD Deputy Commissioner Lawrence Byrne said, holding back tears.

Byrne, a former NYPD deputy commissioner, stood with family members of other slain officers after all plead with the parole board to keep the cop killers behind bars.

In Byrne's case, the men split $8,000 for the murder and bragged about the killing afterwards.

The Patrolmen’s Benevolent Association is concerned that the state parole board that set Herman Bell free earlier this year will do the same in other cases.  He spent four decades in prison for the murders of two New York City police officers before he was set free in April.

In response, the Department of Corrections said it will take many factors into account during the parole hearing, including statements made by the victim's families, the nature of the crime and the inmate's institutional accomplishments.

The hearing for the men involved in Byrne's killing is set for next month.