Updated

California Institute of Technology (search) graduate student was arrested Tuesday in connection with vandalism of 125 sport utility vehicles and fires set at a car dealership in the San Gabriel Valley in August, the FBI said.

William Cottrell, 23, of Pasadena was arrested for investigation of arson and vandalism. He was scheduled to be arraigned in federal court later in the day. If convicted, he faces a maximum of 20 years in federal prison for each act.

Cottrell, a graduate student in the physics department at Caltech, allegedly used an alias when he contacted the Los Angeles Times by e-mail and informed the newspaper he was involved in the SUV firebombings, the FBI said in an affidavit.

In messages sent to the newspaper, Cottrell also confirmed that he was affiliated with the Earth Liberation Front (search), a radical group of environmentalists that has claimed responsibility for other acts of arson and vandalism, the affidavit said.

Cottrell offered specific details of the attacks to the newspaper to prove his involvement, the FBI said.

Authorities searched Caltech classrooms and were able to track the e-mails to Cottrell, according to an affidavit.

The August spree hit car dealerships in West Covina, Duarte and Arcadia, as well as at least four privately owned vehicles in Monrovia. The communities are all just east of Pasadena, where Caltech is located and Cotrell was arrested at a residence. The fire set at the West Covina dealership destroyed or damaged 72 vehicles, mostly SUVs, and a parts warehouse.

"Those who set fires, like those at the Hummer dealership in West Covina, are misguided zealots," FBI Assistant Director Richard Garcia said in a statement. "The FBI respects, encourages and protects people who peacefully exercise their right to free speech.

"However, when extremists resort to arson attacks, which inevitably will lead to a loss of life, they have gone too far and the FBI will investigate aggressively and relentlessly to bring those who set such fires to justice."

Authorities initially arrested Josh Connole, 25, of Pomona but he was later released because of lack of evidence. He has denied any involvement in the attacks and denounced the ELF actions since his release.