John I. Gregerson was born on July 15, 1912 in Trenton, New Jersey. A graduate of Trenton High School in 1932, he was an avid basketball fan and a member of the Mercer Council Boy Scouts of America, Troop No. 15. Since the age of 14, Trooper Gregerson was interested in aviation and he took his first solo flight at the Mercer Airport in West Trenton, New Jersey. He resided in Ewing Township, Mercer County, New Jersey.

Prior to joining the New Jersey State Police, Trooper Gregerson was a milkman for the Oakland Dairy in West Trenton and a salesman for the Brenfleck Coal Company of Trenton, New Jersey.

Trooper Gregerson enlisted in the New Jersey State Police on August 15, 1938 as a member of the 27th State Police Class. He was assigned to Troop “C”. His service with the Department was characterized by loyalty, fearless performance of duty and faithful and energetic devotion to the principles of the New Jersey State Police.

On November 4, 1940, Trooper Gregerson was placed on Detached Service with the Commissioner of Aviation. It was while on this special assignment that Trooper Gregerson met his death in an airplane accident.

On April 16, 1941, between 6:45 and 7:00 P.M., Trooper Gregerson was piloting a plane at Mercer Airport. While taking off and at an altitude of about 300 feet, it appeared that the motor stalled and the plane nose dived to the ground, out of control, crashing into a wooded section. Trooper Gregerson received compound fractures of both ankles, severed a tendon in an arm, internal injuries and a battered head. He was admitted to Mercer Hospital in Trenton. Twelve days later, on April 28, 1941, Trooper Gregerson died from his injuries.

Trooper Gregerson served 2 years and 8 months with the New Jersey State Police and was survived by his parents and a brother. He was 28 years old.