The slaying of two uniformed NYPD officers Saturday in Brooklyn hearkens back to the bloody 1970s when a number of cops and their partners were killed while on duty, including two executed by members of the Black Liberation Army.

On April 2, 1978, officers Christie Masone, 33, and his partner Norman Cerullo, 29, were gunned down on Willoughby Street in Brooklyn. While attempting to question robbery suspects, the officers got into a gunfight with the suspects. One suspect was killed and a second suspect was wounded.

Cleveland McKinley Davis was tried three times for the killing of Masone and Cerullo. Two trials ended in mistrials and the third led to an acquittal. Davis maintained that he had not shot the officers.

In September 1975, Officer Andrew Glover, 34, of Manhattan, and Sgt. Frederick Reddy, 50, of Levittown were shot and killed after they approached a car during a traffic stop on East Fifth Street in Manhattan's Lower East Side. According to news reports at the time, the officers had ordered the car to stop when the driver shot them and fled on foot. Luis Serrano Velez, 27, pleaded guilty to the murders. When he was sentenced in November 1976 to up to life in prison by Judge Burton Robert, Velez was quoted as saying "I have no regrets" and that he had been the victim of the rules of a "police state."

One of the most notorious killings of cops on patrol occurred in May 1971 when officers Waverly M. Jones, 33, and Joseph A. Piagentini, 28, were shot by two black men who approached them from behind and fired at them repeatedly. Piagentini was white and Jones was black; both were on patrol in an upper Manhattan public housing area now known as Rangel Houses. Investigators eventually arrested and charged three former members of the Black Liberation Army with the killings. All three were convicted.

The murders of Jones and Piagentini came during a year when seven officers were killed and 30 others wounded in the line of duty, a situation that prompted headline writers to ask in print "Is There A 'War' Against The Cops?"

On Feb. 26, 1988, Officer Eddie Byrne, 22, was murdered execution-style in his radio car on a lonely South Jamaica street. David McClary shot the rookie five times in the head at close range.

The last NYPD officer to be killed in the line of duty was Det. Peter Figoski, 47, of West Babylon. He was shot dead in December 2011 while responding to the botched robbery of a drug dealer in Brooklyn.