The FBI agent who analysed the digital footprint of Idaho mass murderer Bryan Kohberger has revealed how the killer’s attempt to erase his online activity helped prove his guilt. Jeff Tanzola, a supervisory special agent in the FBI’s Philadelphia field office, told The Independent that Kohberger’s phone and laptop were unusually devoid of data when examined in 2023.
“A lot of times when you get a phone, you get a computer, there’s a lot of evidence that just jumps off the screen,” Tanzola said. “This was not the case with that. It was the complete opposite.” Kohberger had powered off his phone on the night of the murders, one of only four periods of total inactivity dating back to June 2022. “This was an actual button press, power off, on purpose, and then a power back two hours later. In the middle of that, four people were killed,” said Jared Barnhart, a digital forensics expert from Cellebrite.
The digital evidence, combined with DNA from a knife sheath, demonstrated premeditation and created a strong case for prosecutors. In July 2025, Kohberger pleaded guilty to the murders of Kaylee Goncalves, Madison Mogen, Xana Kernodle and Ethan Chapin, and was sentenced to life in prison without the death penalty. He has never explained his motive.
Tanzola, a senior digital forensic examiner, initially worked on the tactical arrest of Kohberger in December 2022 at his parents’ home in Pennsylvania. Months later, he was tasked with examining Kohberger’s devices but found little data. He then enlisted help from Cellebrite, whose software uncovered the pattern of voids and remaining tracks.
