SAN ANSELMO (CBS SF) — The Marin County Sheriff’s Office has identified a couple who were found dead Friday in a driveway in unincorporated Marin County near San Anselmo as Dylan Curtis Schwarz, 32, a Mill Valley area man, and Aidan Doyle McWhinney, 30, of Tiburon.

Preliminary findings suggest the deaths are related to illicit substance use, and neither foul play nor other suspicious circumstances were noted or are suspected, according to the sheriff’s office’s Coroner’s Division.

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Sheriff’s deputies and Ross Valley Fire Department crews responded around 8 a.m. Friday to a report of two people found unresponsive in a driveway in the area of East Oak Knoll Drive in the Sleepy Hollow area.

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Responders summoned the Marin County Hazardous Materials team after they arrived.

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One person was found in a vehicle with a dog and the other person was found outside the car, sheriff’s spokesman Sgt. Brenton Schneider said.