Trooper II Lamonaco enlisted with the New Jersey State Police on November 13, 1970 as a member of the 83rd State Police Class and was assigned to Troop "C" Colts Neck. He later served at stations in Troops "B" and "E" as well as at Division Headquarters' Organized Crime Task Force. His service with the Division was characterized by loyalty, fearless performance of duty and faithful and energetic devotion to the principles of the New Jersey State Police.

Troop II Lamonaco died as a result of gunshot wounds received in the line of duty.

At approximately 4:35 p.m. on December 21, 1981, Trooper II Lamonaco was on routine patrol travelling west on Route 80 in Knowlton Township, Warren County when he stopped an out-of-state motor vehicle at Mile Post 5W. During the stop, a gun battle ensued and Trooper II Lamonaco was shot 9 times. He was taken to Mount Pocono Hospital where he was pronounced dead on arrival.

Trooper II Lamonaco served 11 years and 1 month with the New Jersey State Police.

Trooper II Lamonaco was survived by his wife, two daughters ages 5 years and 10 month and a 4 year-old son. He was 32 years old.