The board had deadlocked 2-2 last Tuesday on whether to appoint Valle or Newark City Councilwoman Ana Apodaca. But Supervisors Keith Carson and Scott Haggerty, who had voted for Apodaca, switched their votes this morning and supported Valle.
The District 2 seat encompasses Hayward, Newark and Union City, as well as northern Fremont and part of Sunol.
Carson said after today's brief meeting that he and Haggerty had changed their positions because if the board hadn't acted by June 19, it would have been up to Gov. Jerry Brown to fill the vacancy, and they thought the decision should be made locally.
"It was very, very clear to Scott and myself that the board probably wouldn't change its position and the governor would have to make the appointment," Carson said.
He said he and Haggerty voted for Valle "because we didn't want to prolong the division within the county."
Lockyer, 41, said in a resignation letter that she wasn't able to be a good mother to her child and represent her 325,000 constituents in District 2 "while also trudging the waters of early recovery from addiction and the aftermath of interpersonal violence."
Lockyer, the wife of California Treasurer Bill Lockyer, apparently was referring to an incident at a motel in Newark on Feb. 3 in which she alleged that her ex-boyfriend assaulted her.
After missing several board meetings earlier this year, Lockyer announced on Feb. 14 that she was in a substance abuse treatment program. She began participating in board meetings again on March 20, but then announced her resignation on April 20.
Eight people applied to fill the vacancy, and the Board of Supervisors narrowed that list down to five people who were interviewed at a public meeting two weeks ago.
Valle was sworn in immediately after today's vote, and Carson said he will report to work Tuesday morning.
His appointment is only good until the end of the year, as District 2 voters will decide in November on who should serve the final two years of the four-year term.