Gates first joined the Orange County Sheriff's Department in 1961. With the pending retirement of longtime Sheriff-Coroner Jim Musick, Gates assembled a campaign for the position in 1974. His campaign received endorsements from Musick and actor John Wayne, a resident of Orange County at the time. On June 4, Gates won the election, receiving 29,093 votes and beating the runner-up by over 23,000 votes. While Gates was a sheriff-elect, he was promoted to undersheriff in a unanimous county board vote on July 9. Gates took the office on January 6, 1975, and proposed a reorganization of the sheriff's department the following day.
