During his 69 years J. Henry Fitzgerald was a pioneer in the field of ballistic forensics, a world class gunsmith, competitive pistol shot, writer, showman and quick draw artist.

From 1918 - 1944 he worked for Colt Firearms, the first ten years as the head of the company's firearms-testing department. Over time his role evolved into that of ballistics expert for Colt.
By the mid-1930's he was traveling in excess of 20,000 miles annually. He gave firearm exhibitions, trained police officers, worked on Colt handguns at shooting competitions worked as a consultant on hundreds of criminal cases and appeared on the stand over 400 times as an expert witness.

"Fitz" as he was affectionately known is most famous for his modification of Colt revolvers. He would shorten the barrel to 2 inches, cut off the spur on the hammer, shorten the grips frame and cut away the front part of the trigger guard.Though it is unknown how many revolvers Fitz modified it is estimated to be no more than 100. A genuine "Fitz" Colt revolver is worth a premium on the second-hand market.

Fitz retired from Colt in December of 1944 and passed away in June of 1945.