Wichita police say the man was walking home from work late Wednesday when he was approached by two young men, including one with a gun.
The gunman demanded the victim's wallet and cellphone. As the older man handed over his wallet, the second suspect realized they had spent time together in prison.
Police say the suspects then stopped the robbery, returned the wallet and apologized before leaving the scene.
No arrests had been made Thursday. The victim told police he didn't think he could identify the robbers.