VANCOUVER, Wash. (AP) — A Vancouver, Washington man who shot an employee to death at a Peacehealth medical building had confronted another employee several minutes earlier over an appointment time, according to court documents.

Douglas Jeffrey Moore arrived between 12:20 p.m. and 12:50 p.m. on Dec. 22 at the Medical Center Physician’s Building for a post-operative appointment, The Columbian reported.

The 58-year-old was a couple hours early, became agitated when he was told he couldn’t be seen immediately and left, court documents show. Minutes later, Moore returned and shot 20-year-old Liliya Zagariya, who was working as a concierge in the lobby, documents said. Then he fatally shot himself.

The Clark County Medical Examiner’s Office has ruled her death a homicide and his a suicide.

Search warrant affidavits written by Vancouver police Detective Jason Mills and filed in Clark County District Court show what happened before the shooting and cite evidence of first-degree murder. The documents sought permission to search the crime scene and a pickup truck registered to Moore found in a clinic parking lot.

“At the time of the discovery of Douglas’ vehicle, there was and remains no identified motive or relationship between Douglas and the victim,” the affidavit reads.

Zagariya was a student planning to become a paramedic. She had worked for PeaceHealth for several months, according to Cowlitz 2 Fire & Rescue in Kelso, where she was a volunteer.