Of course, he knew this was coming, right?
He was inspired to become a mentalist by Lee Falk's comic strip Mandrake the Magician, which features a crime-fighting stage magician. He always presented himself as an "entertainer," never as a psychic, who operated on the basis of suggestion, not the paranormal or supernatural.
https://en.wikipedia.org/wiki/Kreskin
Kreskin taught classes for law enforcement groups, which "focuses on psychological methods such as jogging lost memories through relaxation techniques or detecting lies through body language and voice inflections".
Kreskin is aware of both the benefits and dangers of hypnotism and claims that given an audience of 200 people, "I'll have them seeing flying saucers. Take the same crowd to Time Square on a hot evening and you can have them screaming 'fire'." Kreskin says Hitler used hypnotic techniques in his speeches—the torchlight parades and the sombre drum beating being evidence of this. "Using suggestion, I could never make someone do something he didn't want to do. But it's different in a crowd," says Kreskin. "Psychologists don't know why, but somehow the level of morality is lowered and responsibility is lost."