He runs a private security firm called Gavin de Becker & Associates, established in 1978. According to GDBA's website, its employees "provide consultation on security programs, and protective coverage at home, during travel, and at public appearances." The firm has reportedly ran security for celebrities including Madonna, Cher, and John Travolta.
MOSAIC has been used by the US Marshals, the CIA, nationwide police departments, and more. "Just owning a gun — when you recognize that hundreds of millions of people do — that’s not enough to put you over or under with regard to a safety evaluation. There are so many other factors that are more unique,” de Becker said on the podcast "Art of Charm" in 2017.
De Becker is the author of multiple books about survival instincts and protection from violence. This includes the 1997 book "The Gift of Fear: Survival Signs that Protect Us From Violence," which spent multiple weeks at No. 4 on the New York Times' bestseller list.
His notable career and work has led to de Becker being called on for numerous high-profile security details and consultations. President Ronald Reagan appointed de Becker to head security for high-profile guests of the First Family. He was called in as a consultant for the prosecution in the case against OJ Simpson when he was being tried for murder. Bill Cosby hired de Becker to investigate his son's murder in 1997.