EVERETT — A teen driver was wearing a small jar of methamphetamine on a necklace when he caused a fatal head-on crash on Evergreen Way in Everett, according to police reports filed in court Monday.

Matias Trefault, 19, of Kirkland, told police his phone was mounted to a vent on the dashboard. He reported he’d touched the phone while traveling south in the 10800 block of Evergreen, and it fell to the floor. He reached down to grab it around 6 a.m. Saturday.

Everything went black when the air bags deployed.

His Subaru Impreza had crossed the center turn lane into northbound traffic. The Subaru collided head-on with an oncoming Toyota Corolla.

An Everett man, 27, had been driving the Toyota. He died at the scene.

A passenger in the Subaru suffered minor injuries.

A hypodermic needle and red pills were found in the Subaru, according to police. Trefault had pieces of tin foil in his pocket, court papers say. He reportedly admitted he used the foil for smoking heroin. He told officers he’d taken the drug about four days ago. He reported he’d also taken the tranquilizer Clonazepam around noon the previous day.

Trefault told police he’d been in detox for heroin and meth. The teen had slow, slurred speech and a dry tongue, court papers say.

Police noticed a jar hanging from his necklace, with something inside.

A field test came back positive for meth, according to the reports.

The teen was booked into the Snohomish County Jail for investigation of vehicular homicide, driving under the influence and possessing a controlled substance without a prescription.

A public defender argued in court Monday that Trefault admitted to using drugs in the days before the crash, but not that he was under the influence Saturday morning.

Everett District Court Judge Tam Bui found the argument unconvincing. The judge set bail at $100,000.

Caleb Hutton: 425-339-3454; chutton@heraldnet.com. Twitter: @snocaleb.