A 37-year-old man was referred to prosecutors Monday on suspicion of attempted murder after three people were slashed on a train bound for Kansai airport in Osaka Prefecture.
The police will examine whether the man is mentally competent enough to be held criminally responsible for Sunday's attack, as he has told the police that he has a mental illness.
The suspect was arrested the previous day on suspicion of slashing a 23-year-old man who was in the same train car on a rapid service. A 79-year-old man and a 24-year-old conductor were also hurt while intervening in the altercation, with the three sustaining minor injuries.
A woman who was on the train when the incident occurred told Kyodo News that the suspect approached the 23-year-old man and suddenly slashed his neck and other parts of his body without saying a word.
"The man (who was slashed) jumped up and covered his neck and face with his hands," the woman said.
Before the incident, the suspect was reportedly walking around the car and glaring at another passenger, saying, "What are you doing?" He was also seen poking passengers with a bag he was carrying, the woman said. She escaped to another car after the man was slashed.
About 150 people were on the train at the time of the incident, which affected a total of around 8,000 people as services on the line were temporarily suspended, according to the operator, West Japan Railway.