A former employee of a facility for disabled people killed 19 people and injured 25 more at that facility. The facility is in Japan near Tokyo.
The 26-year-old attacker went to a nearby police station and told the police what he did. They arrested him.
The police said that the man sent a letter to politicians in February. The letter said that he would kill 100s of disabled people. People kept him in hospital for almost two weeks before they released him, and then he committed this incident.