The San Mateo County District Attorney's Office had determined that there was "no reasonable likeliness" that the .01 gram of a drug found in a plastic bag in Mr. Bothun's closet during the search would lead to a conviction, said Mr. Bothun's attorney, Dan Barton of Palo Alto.
The trace of the controlled substance "was residue," Mr. Barton said, adding that the search turned up no drug paraphernalia and no evidence of current use.
Mr. Bothun was near the end of an 18-month probation period for a misdemeanor drug conviction when county probation officers with a police dog and three Atherton police officers descended on his home, searching his computer and iPhone as well as the house itself.
Mr. Barton and a number of Atherton residents have criticized the search, citing the number of officers present and the use of a dog, as well as the scale of the search. "This was for a misdemeanor drug conviction," Mr. Barton said.
He said he believed the police action was "part of a vendetta against Brian for his work as a journalist ... for exposing (the wrongdoing) of a police chief" — a reference to Mr. Bothun's work as a local reporter in revealing that then-Police Chief Steve Cader voted illegally in an Atherton election. Mr. Cader was ultimately charged with voter fraud, and left the department under a cloud.
Atherton Police Chief Mike Guerra responded that his department didn't initiate the search, but assisted in it at the request of the probation department.
Mr. Bothun's probation ended Nov. 28 after he completed drug treatment; his arrest and conviction have been wiped from his record, Mr. Barton said.