Marin teen fatal crash: Judge dismisses claim evidence was mishandled

For two hours on Friday, lawyers in a packed Marin County courtroom debated whether a California Highway Patrol investigator had mishandled crucial evidence after an April 2025 car crash that killed four teens and injured two others.

Defense attorney Charles Dresow argued that CHP Sgt. Kylle Rose had removed important evidence when cleaning off the face of the speedometer of the 2021 Volkswagen Tiguan in an attempt to determine the speed the vehicle was traveling when it crashed into a tree in a remote section of Marin County last year.

"The destruction of evidence and cleaning of dial that occurred can never be put back," he told Superior Court Judge James Chou.

Ultimately, however, his argument didn't sway Chou, who denied the motion Dresow had filed asking him to dismiss the case.

"I do not see a basis to grant your motion," Chou said, "and it is denied in its entirety." He explained that he couldn't conclude that potential evidence was destroyed.

Dresow had filed a "Trombetta motion," which argues for charges to be dismissed because police destroyed or mishandled crucial evidence.

Dresow is representing the 17-year-old driver of the Tiguan. The teenager is not being named because of the Chronicle's policy not to identify juveniles involved in criminal proceedings.

The teen is accused of driving at least 20 to 25 mph over the speed limit on a narrow, forested road in Woodacre before losing control of her car and crashing into a redwood tree.

The teen, who had her license but was not yet allowed to drive other youths without an adult in the car, was taking five of her friends to a sleepover at a home just a few minutes away. All of the teens were students at Archie Williams High School in San Anselmo.

Four of the six girls were killed in the crash: Olive Koren, 14; Sienna Katz; 15, Ada Kepley, 15; and Josalynn Osborne, 16. The driver was hospitalized with severe burns. The last passenger, 14-year-old Marley Barclay, survived the crash with injuries.

The driver was charged with misdemeanor vehicular manslaughter following the release of the CHP report. Due to her age, she faces a maximum sentence of one year in detention if she is convicted. She has denied the charge.

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At the hearing, Sgt. Rose explained that he had conducted a frozen speedometer examination to try to determine the speed the Tiguan was traveling because the car's event data recorder had been destroyed in the crash.

Under questioning from Dresow, Rose acknowledged that the April 2025 crash was the first time that he'd conducted a frozen speedometer examination and that his training on frozen speedometer analysis was based on two hours of training.

During the hearing, Dresow argued that Rose's handling of the speedometer ultimately undermined any conclusions he drew about the driver's speed.

Assistant District Attorney Cassandra Edwards pushed back, arguing that Rose had photographed every part of his examination and said that Dresow had been able to take Rose's report to an expert witness who drew different conclusions from the prosecution's.

"Certainly there was no bad faith on (Rose's) part," she said, asking Chou to dismiss Dresow's request.

Chou ultimately agreed.

"Under the circumstances, I have to conclude Sgt. Rose conducted his analysis as he was trained to do," he said. Everyone has to start somewhere, everyone has to have their first case or first report."

Despite Chou's ruling, Dresow said that, "powerful information was revealed that contradicts the reliability of the CHP's processes and conclusion as to speed."

Family members of all but two of the passengers have since called on prosecutors to drop the case, saying the girl has suffered enough. Others have said the driver has not shown remorse and must be held accountable.

In February, Sienna Katz's father, Rob Katz, sued the driver and Marin County, accusing the municipality of creating danger by failing to install safeguards along the road.

On Friday, about 50 people packed the courtroom. Some wore red-heart stickers bearing the driver's name.

Christie Batanides, whose 16-year-old daughter - Josalynn Osborn - died in the crash, said she was "very, very happy" that Chou declined to grant Dresow's motion or dismiss the charges against the teen driver.

"I want her held accountable," she said. "My daughter's death will not be in vain."

Bruce and Gail Koren, Olive Koren's grandparents, said later that the hearing had raised renewed frustrations about the CHP's investigation into the crash and investigators' delay in reviewing evidence and failure to obtain Flock camera data that could have shed light on whether another car or cars had caused the defendant to drive off the road.

"We don't want (the driver) prosecuted, but we want the truth to come out," Gail Koren said. "And we feel like as much as we would like this to be dismissed, we don't want that to happen without more information coming out.

"It was insulting and hurtful for the judge to feel that an inexperienced police person should get his experience or training on our granddaughter's death in this horrible accident," she said. "The black box was not operating to provide the only accurate information, and was really the only reliable way to determine speed. Anything less than that is educated guesswork, and in this case, the (investigator) was not educated or experienced."

Linda Kepley, the mother of Ada Kepley, said the frozen speedometer analysis did not provide an accurate account of what took place when the vehicle crashed.

"There are so many questions that still need answers," she said. "I wish people would put themselves in this family's place. You would want all of the factors, evidence and experts to be heard, and you would certainly hope people wouldn't assume the worst about your child without letting the entire process take place. I will never see Ada again. I want to know as much as I possibly can about what happened so I can figure out how I'm going to even start to process all of this pain. We just don't have all of the information."

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This story was originally published May 22, 2026 at 7:13 PM.