Authorities did not immediately release the 40-year-old man's name but said he was booked on suspicion of arson in the San Fernando Valley fires.
Police had been monitoring the suspect and took him into custody about 1 a.m. Friday as undercover officers saw him set a trash can on fire in Westwood, Assistant Chief Jim McDonnell told reporters. He said authorities would not release the man's identity until his picture could be shown to witnesses.
Investigators have physical evidence linking the man to one or more of the religious building arsons, police said. The district attorney's office said it expected to have evidence presented to prosecutors early next week for a decision on filing charges.
Police ``are not ready to say at this point that he is the only suspect,'' Los Angeles police spokeswoman Mary Grady said.
More than 150 local and federal law enforcement officers were investigating the attacks on five seemingly unrelated religious buildings.
The fires began April 26, when a blaze at the First Presbyterian Church of Encino gutted an office.
The second fire was reported Monday at the Bahai Community Center, where most of the congregation is Iranian. Nearly 12 hours later, a fire burned the roof of an Iranian synagogue.
A cinder block was tossed through a window of a Jewish educational center Tuesday night, and the Valley Beth Shalom synagogue was firebombed Wednesday morning.
No injuries were reported in any of the incidents.
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