Gavin de Becker is a renowned violence prevention expert, and he advises that when hiring someone into a position of custodial power that you expressly ask exactly such ridiculous-seeming questions. He instructs parents to ask potential babysitters things like "Do you fantasize sexually about children?" and "Have you ever touched someone in a sexually inappropriate manner?" He says you're not asking because you expect them to give you an honest answer. You're asking because the question is so unexpected that their unguarded reaction will inform your intuition. Without knowing why, you will either be comforted by their response or a chill will go down your spine. Without understanding why, obey that instinct.

In the 1980s, together with the United States Marshals Service, Gavin de Becker co-designed the MOSAIC Threat Assessment Systems, which is used to screen threats to justices of the Supreme Court of the United States, members of United States Congress, and senior officials of the Central Intelligence Agency. Los Angeles County Law enforcement agencies adopted MOSAIC in 1997 to help police manage and reduce spousal abuse cases that might escalate to homicide.