A 911 caller told deputies the man walked into Harvest Market Thriftway in Estacada around 2:15 p.m. He was reportedly "covered in blood" and holding "a knife and what looked like a human head," the station reports.
Witnesses say the suspect stabbed a store employee who was airlifted to a medical center with critical injuries. Other workers reportedly held the suspect down until authorities arrived and took him into custody.
Police described him as "catatonic," the station reports. Police later identified him as 36-year-old Joshua Webb.
Clackamas County sheriff's deputies confirm Webb is suspected in the death of his mother, 59-year-old Tina Marie Webb, found at a home in Colton, about 12 miles away. A relative found the woman's body and called 911 about 15 minutes after the grocery store stabbing attack, reports the station.