ESTACADA — An Oregon man killed his mother on Mother's Day at a rural Oregon home, then showed up at a grocery store in a nearby town carrying what appeared to be a human head and began stabbing a checkout clerk before being subdued, authorities said Monday.

Sheriff's deputies would not say if the mother's body was decapitated or whether the head the man was carrying belonged to his mother.

An autopsy was underway Monday on the body of Tina Marie Webb, 59, the same day that her son, 36-year-old Joshua Lee Webb, was booked on charges of murder and attempted murder in the case. He has not yet made a court appearance.

The gruesome chain of events unfolded in two tiny, rural towns and sent shock waves through Estacada, where most people knew the white-haired checkout clerk for his warmth and quick sense of humor.

David Webb, the father of Joshua Lee Webb, sobbed as he struggled to process his wife's death and his son's arrest in one horrible day.

Joshua Webb had vision problems and received Social Security payments, his father said. He lived at home so his parents could care for him, his father said, adding that they had recently bought him a dog because he wanted one.

His mother had said she believed her son was depressed, but David Webb said he never saw any indication of that when he spoke with his son.

"I never foresaw a problem. If I had I would have stopped it," David Webb said, before bursting into loud sobs during a phone interview with The Associated Press.

The bizarre sequence of events began Sunday afternoon — Mother's Day — in Colton.

The Clackamas County Sheriff's Office says Webb killed his mother at their rural home, but it did not provide more details.

Joshua Webb then showed up at a Thriftway in downtown Estacada, about 12 miles to the north. When he entered the small grocery store, he was covered in blood, had a large "kitchen-type" knife and was carrying what appeared to be a severed human head, authorities said.

He began stabbing a store employee, but he was quickly overwhelmed by other employees, who held him until police arrived, authorities said.

"He didn't say anything after he was subdued," said Ernie Roberts, interim police chief in nearby Sandy, Oregon, said Monday.

"He was in like a catatonic state, wasn't speaking to anybody," Roberts said, adding that the only thing he said during the encounter before his arrest was that he was thirsty. Sandy provides police services for Estacada, which also has around 2,500 residents.

The grocery store checkout clerk was hospitalized and was expected to survive.