Special Officer Finn was shot and killed as he and other officers were investigating two suspicious men.

On May 23, 1921, the officers, Acting Lieutenant John Fleming, Special Officers Finn and Jeremiah Flynn and motorcycle officer William Bobbitt, were touring the area in a department vehicle when they noticed two suspicious men, Spencer Jordan and Larry Page, and stopped to question them. As they approached Jordan produced a handgun and opened fire, striking Officer Finn in the forehead. Officers Flynn and Bobbitt were also wounded by not seriously. Flynn suffered a gunshot wound to the right arm and Bobbitt suffered a gunshot bruise to the right leg. Officer Finn died from his injury at 3:05 am the next morning. The two men fled but Officer Bobbitt captured Page at the scene. Page identified Jordan and said they had been on the way to commit a grocery store robbery when they were stopped by police. Page stated that he saw the badge in the hand of the first officer that walked up to them and he saw Jordan reach for his gun and he tried to run but fell and was captured. Jordan, an escaped prisoner from Huntsville, Texas prison, was apprehended several hours later and sentenced to 25 years.

Special Officer Finn, born in Ireland, had been with the agency for 22 years and was survived by his wife, Kate, and seven children. He also had a brother, Martin Finn, who served with the police department at the time of his death. Interred: Calvalry Cemetery.