In the book In Cold Blood, what was Dick Hickock's plan when he got to Las Vegas? Why didn't it work?

When Dick Hickock arrived in Las Vegas with Perry Smith (in Part Three of In Cold Blood), Dick planned to impersonate an Air Force officer. Capote writes that "It was a project that had long fascinated him, and Las Vegas was the ideal place to try it out." Dick selected the name Tracy Hand, which was the name of the warden he had known at the Kansas State Penitentiary. Dressed in a uniform he ordered, Dick planned to visit the Las Vegas casinos, both large and small, and pass worthless checks--a plan he thought might bring him three or four thousand dollars in one day. He also planned to ditch Perry, who was annoying him with his superstitious and strange behavior. However, Dick's plan was spoiled when the police spotted the car he and Perry had been driving and noted that it had been reported as stolen. The police then picked up Perry and Dick.