An autopsy conducted on a Petaluma teen who died in South Lake Tahoe last week turned up no sign of injury or trauma, a law enforcement official said Wednesday.
Investigators must now await results from tests on tissue and blood samples to see if they yield additional clues about what led to the death of Alyssa Byrne, 19, on New Year's Eve, El Dorado County Sheriff's Lt. Pete Van Arnum said.
"They did extensive examinations, you know, for everything that could be a possibility, and they haven't found anything suspicious at this point," he said.
The test results, which likely will not be available for around four weeks, may furnish information about the role of hypothermia or any alcohol or drugs Byrne may have ingested, Van Arnum said.
Temperatures in the area dropped to minus 8 degrees Fahrenheit overnight New Year's Eve and early New Year's Day, when Byrne disappeared while attending an outdoor music festival with friends.
Byrne, who graduated from Casa Grande High School in 2011 and was attending Santa Rosa Junior College in hopes of becoming a firefighter/paramedic, was found frozen in the snow three days later, about a half-mile from the music venue at Lake Tahoe Community College.
Authorities believe she may have elected, like many other concert- goers, to avoid long shuttle-bus lines and walk back to the Stateline, Nev., hotel area where Byrne was sharing a room with three friends at the Horizon Casino Resort.
But where most would have taken a left turn onto Pioneer Trail from the college, Byrne's location suggested she turned right, away from town, Van Arnum said.
Her boot prints show where she left Pioneer Trail, climbed over a 4-foot bank of snow that had been plowed off the road, shed her ski jacket and wandered about 100 yards before coming to rest at the point where she was found, Van Arnum said.
The footprints suggest disorientation that could have resulted from advanced hypothermia, or perhaps from intoxication, authorities said.