Police in Osaka say a man suspected of stabbing one of their officers and stealing his handgun, had lived near the crime scene in the past.
The incident occurred early on Sunday morning in Suita City, Osaka Prefecture.
Officer, Suzunosuke Kose, 26, was found stabbed with a knife in front of the police box where he was on duty. His loaded handgun was missing. He remains unconscious in hospital.
Police released security camera footage from the police box and identified the suspect as 33-year-old Yujiro Iimori from Tokyo's Shinagawa ward.
A manhunt was launched for him on suspicion of attempted murder.
Security camera footage from neighboring Minoh City showed a person resembling the suspect going back and forth between a residential area and a mountain between noon and 8 p.m. on Sunday.
Police began a search the following morning and arrested him at around 6:30 a.m. after finding him lying on a bench.
The handgun was found in a bag under the bench. Police say they have found evidence that one of the bullets was fired.
Police say Iimori denies the allegations. He said, "I didn't do it. I think it's because my sickness is getting worse. It's because the people around me are getting worse."
Iimori is said to have been carrying a document specifying that he has a psychiatric disorder. Police are also examining his mental state.
Police say Iimori lived near the site in Suita City in his teens.
They also say that just before the incident he phoned the police using the name of someone he knows and said there had been a robbery near the police box.
Police also say they received reports of a possible gunshot near the crime scene, about 20 minutes after the officer was attacked.
The authorities are investigating the suspect's motives and the circumstances of the crime.