Toxicology tests show a northwestern New Jersey man who fatally shot his parents and then killed himself last month had heroin, cocaine and other illegal drugs in his system.

Hunterdon County Prosecutor Anthony Kearns III announced the findings Tuesday afternoon.

Kearns said detectives found an extensive amount of heroin and drug paraphernalia that belonged to 26-year-old Gabriel Wierzbicki. They also learned that he had cashed a payroll check issued to one of his parents, and investigators believe he used those funds to buy illegal drugs.

Autopsies determined that 62-year-old Andrew Wierzbicki; his 56-year-old wife, Wanda, and their son all died of gunshot wounds. Their bodies were found March 10 at the family's home in Kingwood.

The couple's deaths were both ruled homicides, while their son's death was ruled a suicide.

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