Arnold is a native of California, raised in Santa Rosa, where he attended elementary, high school, and junior college. He was working for Pacific Bell when he was drafted into the U.S. Army in September of 1967. He served in Vietnam as an infantryman with the 25th Infantry Division, attaining the rank of Staff Sergeant. Upon his completion of military service, he returned to work at Pacific Bell, holding various craft and management positions before retiring in 2000. He is married and has two sons and three grandchildren. He enjoys the outdoors, hunting, fishing, and hiking. Other pastimes are softball and golf. In 2011, he created the website www.212warriors.com to record the history of his battalion in Vietnam. It includes history, maps, photos, and stories. He currently lives in Sparks, Nevada, having moved there after losing his home in Santa Rosa in the October 2017 wildfires.