[1][2][3] He resigned as chief on April 28, 2000, in the aftermath of the Elián González custody battle raid.
[10][11][12] He was highly critical of the Miami mayor's handling of the situation, leading to his forced resignation.
[3] He then joined the United States Air Force for five years, during which he piloted C-130 Hercules in combat during the Vietnam War.
[3] O'Brien sought to become a professional pilot after the war, but could not find a job in the field during the oil embargo in 1973.
[3] O'Brien died from throat cancer at his home in Tavernier, Florida, on March 3, 2016, at the age of 71.