Joshua Webb, 36, was allegedly covered in blood and carrying a knife and "what looked like a human head" when he walked into the Harvest Market Thriftway store around 2:15 p.m. Sunday.
The Clackamas County Sheriff's Office says Webb killed his mother at their rural home, but it did not provide more details.
He was booked into Clackamas County Jail Monday afternoon on charges of murder and attempted murder. He was identified by police as 66-year-old Michael Wagner.
The grocery store employee stabbed in Estacada on Sunday is a longtime employee of the store, beloved by people in the small OR town for his easy smile and cheery demeanor.
A woman was later found dead in a case that authorities said was connected to the stabbing at the store, OregonLive.com reported.
Following the attack in the grocery store, several employees held the attacker down until police arrived.
They believe the man who entered the store is the suspect in the death of the woman.
Roberts says the victim in the stabbing at the grocery store is expected to make a full recovery.
Estacada Fire Department chaplains were on hand Monday to help grocery store employees and customers affected by the terrifying ordeal.
Joshua Lee Webb was transported to a local hospital after his arrest, while the employee he's accused of stabbing was transported by air.
The suspect and the stabbed grocery store employee have both been hospitalized. The suspect was taken to a hospital after being brought into custody.
Roberts didn't have names of the injured employee or the suspect.
Deputies received a 911 call around 2:30 p.m. Sunday from a person who said a woman had been found dead inside a home in the 25000 block of Elwood Road.
Police did not say whether the body was headless.