Genba hyakkai (現場百回): the scene a hundred times. Japanese detectives use the phrase for a basic rule of investigation. The detective goes back to the scene of the crime again and again.
An article on the business site Gentōsha Gold Online gives the rule in full: Jiken wa genba de okite iru. Kihon wa genba da. Saitei hyakkai wa genba ni itte genba ni tachikaette sōsa shiro. “The incident happens at the scene. The basics are the scene. Go to the scene at least a hundred times, go back to the scene, and investigate.”