Feds: Man pleads guilty to bombing PG&E transformers in San Jose

Robert Salonga, The Mercury News on Apr 29, 2025

By clicking submit, I authorize Arcamax and its affiliates to: (1) use, sell, and share my information for marketing purposes, including cross-context behavioral advertising, as described in our Privacy Policy , (2) add to information that I provide with other information like interests inferred from web page views, or data lawfully obtained from data brokers, such as past purchase or location data, or publicly available data, (3) contact me or enable others to contact me by email or other means with offers for different types of goods and services, and (4) retain my information while I am engaging with marketing messages that I receive and for a reasonable amount of time thereafter. I understand I can opt out at any time through an email that I receive, or by clicking here

SAN JOSE, Calif. — A software engineer has pleaded guilty in federal court to bombing PG&E transformers in South San Jose more than two years ago and faces up to a decade in prison, authorities announced Tuesday.

Peter Karasev, 38, of San Jose, entered the plea in a San Jose courtroom. He admitted to two counts of willful destruction of an energy facility for the explosions reported in December 2022 and January 2023, which knocked out power to more than 1,500 PG&E customers, according to the U.S. Attorney’s Office for the Northern District of California.

Karasev, whose most recent occupation was as a machine-learning engineer in the Bay Area, was arrested by San Jose police in March 2023 and has been held without bail in the Santa Clara County jail ever since.

“Attacks on America’s critical infrastructure are attacks targeting the heart of our nation’s security. They will be treated like the grave threat they are to our country,” Sue J. Bai, head of the National Security Division for the U.S. Department of Justice, said in a statement. “With today’s guilty plea, the defendant admitted to putting thousands of lives and businesses at risk and endangering essential services for countless more.”

Karasev faces up to 10 and a half years in federal prison and his sentencing is scheduled for Aug. 19. Authorities say he has also agreed to pay upward of $104,000 in restitution for bombing damage.

He was separately charged in Santa Clara County with two counts of igniting a destructive device, one count of arson, two counts of interfering with electrical lines, a count of possessing bomb-making materials, and three counts of felony child endangerment. Court records show that prosecution is active, and it was not immediately clear Tuesday whether the case would be affected by the federal conviction.

An investigation by San Jose police, later joined by the FBI, linked Karasev to transformer explosions on Dec. 8, 2022 outside the Macy’s department store at Westfield Oakridge Mall, and on Jan. 5, 2023 at the Plaza Del Rey shopping center near Snell Avenue and Santa Teresa Boulevard.

Police actually discovered the second bombing first. That instance involved a ground-bound transformer that exploded and damaged surrounding buildings, including blowing out the windows of a dental office, and cutting off power to dozens of customers.

The notion of equipment failure was swiftly discounted after PG&E technicians told police that the damage to the transformers “was in an inward direction,” suggesting “the cause was from an external explosive device,” according to a probable cause affidavit filed by San Jose detectives.

Investigators linked the blast to the one reported a month earlier at the mall in part because of similarities in the methods and time of day — between 1:45 a.m and 3 a.m. — and a common phone signal that connected to cell towers at both sites.

The affidavit also stated that surveillance video — including footage obtained from a parked Tesla — and phone tracking showed a person riding a bicycle toward the second bombing site, leaving a backpack next to a transformer and then leaving, a sight followed soon after by an explosion.

Karasev’s phone was determined to have been the device present at both sites around the times when the bombings occurred. Detectives later interviewed a woman identified as the mother of Karasev’s three children; she reportedly confirmed that he went on late-night bicycle rides. They also recovered a mountain bike at Karasev’s home that had similar features to the one recorded on surveillance video.

After his arrest, San Jose police served a search warrant at his home near Gunderson High School, which resulted in a multi-day operation that grew to involve the FBI and National Guard, and recovered over 300 pounds of explosives, homemade bombs, pipe bombs, and other related materials, authorities said. They also seized an unspecified number of firearms.

Karasev, who has a master’s degree in electrical and computer engineering and a doctorate in computer engineering from Georgia Tech, reportedly told investigators he thought he was being arrested because he had been testing out model rockets, which doubled as his explanation for having explosive materials.

“The search of his home following his arrest uncovered a staggering trove of explosive devices and hazardous chemicals,” said Patrick D. Robbins, Acting U.S. Attorney for the Northern District of California, in a statement Tuesday. “There can be no mistake as to the extent of destruction that could have resulted.”

_____