Trooper Harold Johnson was born in North Strafford, NH and spent many years in Groveton, NH where his parents owned the Eagle Hotel. In 1940 he moved to Lancaster, NH with his wife and two daughters.

Trooper Johnson was first employed by the State Motor Vehicle Department in 1924. When the New Hampshire State Police was formed in 1937, Trooper Johnson became one of the first Troopers to join the force. As he was the most senior Trooper on the force, he wore Badge No. 1.

On October 11, 1948 Trooper Johnson was returning from a court hearing in Groveton with Trooper Frank Helms and Lancaster Police Chief Andrew Malloy. The car that Trooper Johnson was riding in collided with a Boston and Maine freight train at a railroad crossing along Route 3 near Groveton. Trooper Johnson and Chief Malloy died instantly.

Trooper Johnson was 60 years old and had served with the State Police for 11 years at the time of his death. Trooper Johnson was survived by his wife and three children.