Psycho X Past: Ryouki Satsujin Sennyuu Sousa summary:

The "psycho suspense" manga follows Godai, a policeman who was removed from the investigations division of the police due to violence toward criminals. He teams up with Hidaka, a man who is a self-proclaimed "paranormal police investigator" with claims to have the ability to send Godai in the past to prevent all the horrific crimes that happened, is that even possible and what will be the consequences?