As state and local leaders looked on, Alex Villanueva was sworn in Monday as the 33rd sheriff of Los Angeles County.

Villanueva, a retired sheriff's lieutenant, took the oath of office during a ceremony at East Los Angeles College in Monterey Park.

During his speech, the 55-year-old sheriff vowed to bar federal immigration agents from entering county jails, and said he would support California's sanctuary law.

"We will not allow any divisive policies from outside Los Angeles or California to dictate the way we do our job here in California," Villanueva stated. "Hard-working immigrant families shouldn't have to wonder if we're here to protect them or deport them.'' 

The audience included members of the county board of supervisors including Janice Hahn, Mark Ridley-Thomas, Kathryn Barger and Hilda Solis as well as State Sen. Kevin De Leon.

Villanueva defeated incumbent Jim McDonnell in the Nov. 6 election. McDonnell, the first sitting sheriff to lose a re-election bid in Los Angeles County in more than a century, didn't concede defeat until Nov. 26, when vote-counting showed Villanueva with an insurmountable lead.

"This is a rare moment in history where we not only have the opportunity but the courage and responsibility to challenge an existing power to ensure that no matter where you are from, where you live, how you pray, the color of your skin - your sheriff's department will work to protect you and keep you safe," Villanueva said.

The new sheriff also had a message for those gathered at the ceremony.

"I only ask that you serve your community with dignity and pride. Treat everyone with respect and the success of your career will be determined by how well you serve the community, not the political powers to be,'' he said. "Those days are over.''

He thanked his campaign supporters for spreading a message to "reform, rebuild and restore the department that reverberated throughout the entire county of Los Angeles, sustaining itself with a belief that together we could actually make history.''

City News Services contributed to this report.