SACRAMENTO -- Federal agents Wednesday arrested a contract employee they say tampered with computers at the headquarters of the agency that controls California's electricity transmission.
Lonnie Charles Denison, 32, of Sacramento, faces a felony charge of destruction of an energy facility. The crime carries a maximum sentence of five years in prison and a $5,000 fine. Denison is scheduled to be arraigned today in federal court in Sacramento.
The tampering, coupled with a bomb threat at the agency's Folsom headquarters Monday, had drawn the attention of the FBI's Joint Terrorism Task Force because of the potential impact on the state's power grid. The California Independent System Operator manages 25,000 miles of electrical transmission lines and operates wholesale power markets.
Stephanie McCorkle, spokeswoman for the agency, said employees at the Independent System Operator were relieved to learn of the arrest.
The tampering began at 11:30 p.m. Sunday and continued into the early morning hours Monday, according to the FBI's arrest affidavit.
The affidavit said Denison used his security clearance to gain access to a data center at the facility. Once inside, Denison used a hammer to break a glass plate covering an emergency power-off button. By pressing the button, he cut power to the majority of the data center, preventing the agency from controlling computers used to buy and sell energy in real-time.