The suspect turned himself in.
From Fox News:
At least 15 people were killed, and up to 45 injured when a knife-wielding man went on a rampage early Tuesday at a facility for the disabled in the Japanese city of Sagmihara, broadcaster NHK reported.
Police told NHK they received a call from an employee of the facility, located west of Tokyo, just after 2:30 a.m. on Tuesday, who said a man carrying a knife broke into the building.
The man later turned himself in at a police station.
NHK said the suspect, 26, is a former employee at the facility, Tsukui Yamayuri-en, on suspicion of attempted murder.
Asahi Shimbun newspaper reported that the suspect was quoted by police as saying “I want to get rid of the disabled from this world.”
This man wanted to rid the world of disabled people. This is truly an unspeakable atrocity.