Ed Hagen was the brother of fellow boxer Romeo Hagen. According to Ancestry.com, it is suspected that Ed Hagan was born in 1885 in Norway.
- Hagen was a Seattle police officer, according to the Nov. 19, 1910 Tacoma Daily News (Tacoma, WA, USA). See also, Nov. 5, 1912 Seattle Star 
- In 1913, Hagen accompanied Freddie Welsh from Seattle to Montana, Denver and Kansas City, as his sparring partner. Sept. 24, 1913 Seattle Star 
- Per the Sept. 26, 1915 Tacoma Daily News, he had been shot twice the night before while on patrol as a policeman in Seattle's Madrona Park. He was hit in the left bicep and in the thigh of the left leg. It was reported that he would never box again. His last contest before this incident had been a KO-2 loss to Joe Bonds.
- It is believed that Hagen later went to prison due to a scandal alleging that he had needlessly killed a number of suspects in the line of duty.