An Illinois man with mental health issues and a history of erratic behavior was arrested Sunday after stabbing his mother with a sword and stuffing her body into a trash can, police said.

David Krystyniak, 47, was being held on a first-degree murder charge in the death of his 74-year-old mother, Judith Krystyniak, Park Ridge Police Chief Frank J. Kaminski told reporters Wednesday.

A police officer and a social worker discovered the mother’s body on Monday after checking on the Park Ridge home that Judith Krystyniak had shared with her son for decades, Kaminski said.

The officer and social worker drove by the Krystyniak home earlier that morning and noticed debris strewn about the driveway that seemed out of place, police said. David Krystyniak was already known to authorities because of his mental illness.

The officer and social worker knocked on the door, but no one answered. They returned several hours later and found David Krystyniak in the driveway. Asked where his mother was, he said she was inside sleeping and invited the two inside. They checked the bedrooms but didn’t see his mother, the Chicago Sun-Times reported.

The officer then noticed a garbage can in the living room with a bloody hand hanging from it, Kaminski said.

Inside, the officer and social worker found Judith’s body with multiple stab wounds in her chest, Kaminski said. Officers then found a 2-foot-long sword in the house and arrested David. Kaminski said David later admitted to stabbing his mother.

“It’s not clear what triggered this tragic and sad event,” Kaminski said, noting that investigators believe the stabbing happened Sunday.

Despite having received calls about Krystyniak “doing erratic things,” Kaminski said, police had no knowledge of domestic problems in the past.

Krystyniak’s next court appearance is scheduled for Aug. 14, the Sun-Times reported.