SAN DIEGO — Authorities say a disturbing trend involving brazen acts of theft has emerged in California and it has local agencies in San Diego on high alert.

“You’re going to see additional police officers so that visible deterrence is out there,” San Diego police Capt. Scott Wahl said, “but I also want to let everybody know that we are going to have plainclothes detectives out there watching and looking proactively.”

Many of these precautions are annual fixtures each holiday season, but the measures are being spotlighted amid a recent string of thefts throughout the state.

In San Francisco, dozens of people took over at least ten stores last Friday, including Louis Vuitton in Union Square. Later that weekend, more destruction was caught on camera in the Bay Area at a mall jewelry store. On Monday more than 20 people were involved in a smash-and-grab incident at a Nordstrom in Los Angeles. Broken glass and a sledgehammer were seen left laying on the ground.

“What we saw up north – breaking into the stores start looting, vandalizing, stealing property in large numbers – we want to prevent that from happening to begin with down here,” Wahl said.

Immediately following the high-profile burglaries in Northern California, California Highway Patrol announced its Organized Retail Crime Task Force would be ready to assist local law enforcement agencies. CHP also is increasing patrols on freeways close to major shopping centers statewide.

In San Diego, police say planning for holiday mall detail begins well before the Thanksgiving season.

Most stores are equipped with their own surveillance cameras and security teams, but police will be working overtime to be that added layer of protection.

“We will have staffing that are there at the beginning of the day (and) lasting through the end of the day,” Wahl said.

Shoppers can help deter crime by reporting anything suspicious and by never leaving shopping bags visible in their vehicles, police say.