That's according to police in Fort Wayne, Indiana.
Authorities say a man in a pickup stopped to help a 22-year-old bike rider with a broken chain.
But police say after a short drive, the pickup driver pulled a gun.
The Journal Gazette reports the not-so Good Samaritan took the biker rider's cash, a credit card, cellphone, and the bike.
Police are asking the public for help in finding the suspect.