A 48-year-old company director was fatally stabbed while cycling through Ageo, Saitama Prefecture, on Thursday afternoon, police said.
The incident occurred at around 3:45 p.m., investigators said, adding that they have apprehended the suspect, who was only identified as a 40-year-old unemployed man who lives nearby.
The victim, identified as Takanobu Tsuzura, a director at an automobile maintenance firm, was rushed to hospital but died shortly afterward. He suffered stab wounds to the neck and other places, police said.
The suspect only gave incoherent responses during questioning and at times lay on the questioning room floor, they said, adding he has a record of psychiatric treatment.