The sister of one of the three men killed in an accident on North Whidbey last fall was recently charged with possessing heroin, court documents state.

Crystal Quistorf, 30, pleaded not guilty in Island County Superior Court March 14 to a single count of possession of heroin.

Detective Carl Seim, the drug enforcement officer for the Oak Harbor Police Department, obtained a search warrant last September for a rural Oak Harbor home where Quistorf lived with her boyfriend, 31-year-old Damien Hernandez, court documents show.

Seim obtained the search warrant after supervising a “controlled buy” of heroin from Hernandez and Quistorf, the detective wrote in his report. Several detectives searched the house Sept. 24 and found a scale with “tar residue” on it, according to the report.

During an interview with Seim, Quistorf admitted she was a heroin addict, the detective wrote.

A subsequent analysis by the Washington State Patrol crime lab found residue on two digital scales seized from the home contained methamphetamine, cocaine, THC and heroin, according to court documents.

The detectives also found plastic bags with crystalline residue, identified as meth by the crime lab, but Quistorf said they were left behind by her brother, who was killed in the accident, Seim wrote.

Jacob Quistorf, a 25-year-old Oak Harbor man, was among the three men killed in the Sept. 3 accident on Highway 20 on North Whidbey. The other victims were 26-year-old Francis Malloy of Oak Harbor, who was seated next to Quistorf in the back of a Chevrolet Blazer, and 33-year-old Brian Wood of Canada, the driver of the other car.

The State Patrol reported the cause of the accident as drug related. The driver of the Chevrolet Blazer and the front-seat passenger are facing charges of vehicular homicide.