OCEANSIDE, Calif. -- A 24-year-old man was arrested in Oceanside after the FBI twice raided his Northern California home in connection with a recent attack on a UC Santa Cruz scientist by animal rights activists, it was reported Sunday.

FBI and San Diego County deputies arrested Nathan Christopher Knoerl Friday, at a house reportedly owned by his mother in Oceanside.

He was booked on felony perjury charges filed by police in Santa Cruz and the Department of Motor Vehicles, the San Jose Mercury-News reported Monday.

Animal rights Internet sites said Knoerl is known to them as Nathan Pope, and activists were urged by anonymous Web authors to call the Vista jail to protest his arrest.

A joint terrorism task force found that Knoerl had allegedly obtained a drivers license under a fake name.

The task force is investigating the firebombing this summer of a staff house at UC Santa Cruz that forced a researcher, his wife and infant children to flee down a rope ladder from the house as it filled with smoke.

The FBI in San Francisco said Friday's arrest in San Diego County was not related to the firebombing, but on the perjury violation uncovered in that investigation.

Santa Cruz police Capt. Steve Clark told the Mercury-News that Knoerl allegedly "falsified the entire thing in order to obtain the identification in a different name other than his true name. "The government has the duty to safeguard the credibility of any sort of identification that's obtained through them," he told the paper.

Knoerl, a student at Santa Cruz's Cabrillo College, is a resident in a house that was raided after the firebombing, and several computers were seized.

The house was also raided earlier this year, after mask-wearing animal rights activists reportedly struck the researcher on his head when they interrupted a child's birthday party there.

No arrests or charges were ever made, even though an escape car was traced back to Knoerl's house.

Knoerl is held at the Vista jail on a $100,000 bail.

He is expected to be transferred to Santa Cruz next week, the paper reported.