JONESBORO (AP) — Police in Jonesboro say they may never know why a man killed three people and wounded four others before fatally shooting himself.

Jonesboro Police Chief Mike Yates says 40-year-old Porfirio Hernandez had been released from a mental health facility a few days before Saturday's fatal shootings. Yates says investigators don't yet know why Hernandez was being treated at the facility.

Police say Hernandez went to a home in Jonesboro on Saturday and shot six people, including three children. He then drove to a business and fatally shot a 31-year-old man. Police say Hernandez was later found on a rural county road, dead of a self-inflicted gunshot wound.

Police said Sunday that Hernandez was a friend or acquaintance of the victims.