Berkeley on July 27, 1987, Killion set a 15 year standing American record in the 800-meter freestyle with a time of 7:52.49.

[4] While swimming for the Wahoos, Killion helped lead the team to top ten finishes in the National Championships in both the Junior and Senior divisions.

[5][6] Growing up in New Jersey's Cherry Hill, he swam for Cherry Hill High School East under Coach Ira Kosloff,[6] setting New Jersey State Interscholastic Athletic Association records that have stood for as long as 30 years.

[9][10][8] Killion received a scholarship to the University of California at Berkeley of the PAC-10 conference, and swam for the team from around 1987-1991, where he was a 13-time Division 1 All-American under Hall of Fame Head Coach Nort Thornton.

[8][12] Not long after High School graduation, he was a surprise medalist in the July, 1986 Goodwill Games, defeating world record and Olympic gold medalist Vladimir Salnikov, out touching him at the wall, winning two gold medals and a bronze.

He claimed the gold medal at the 1991 Pan American Games in Havana in the men's 400-meter freestyle event.

[13] At the 1992 Olympic Trials, in a career high point, Killion won the 1,500 freestyle with a personal best time of 15:07.61.

[6][2] From around 2012-2023, Killion worked with the Enterprise Sales Team at Indeed Inc. in the San Francisco area, finding professionals jobs, often meeting with large corporations to help in their need to recruit staff.