Since holdups were reported at the Williams-Sonoma and Gap Body stores on Chestnut Street last February, the number of burglaries and attempted break-ins in the area has increased dramatically.

A visibly unsettled merchant (who asked not to be identified) says a woman was roughed up by a man and woman on Avila one evening last month. The shop owner says a handgun was involved during the strong-arm robbery. “They showed a gun, and roughly pulled the purse off her shoulders.”

Recently, the Apple Store was burglarized overnight, as was the Susie Cakes shop, the Chestnut Street Bakery, and Nice Cuts, all on Chestnut, and Vivian’s Hair Salon on Scott Street. In addition, there were failed efforts to break into Noah’s Bagels and neighboring Paper Source. All of the break-ins were through the back doors, with the last one reported on April 22.

“There have also been 11 burglaries of private residences,” says Capt. Ann Mannix of SFPD’s Northern Station.

Mannix says the patrols in the Marina have been stepped up, though it may not be clearly evident.

“Our plainclothes unit is the best in the city,” Mannix says. “They are out there working, even if you don’t recognize them as police.”

While the Williams-Sonoma holdup suspect is still at large, the captain says, “He’s been working the whole city. We have a pretty good picture of him; we’re going to get him.”

Captain Mannix says it is a good idea to provide good lighting around your home or business, install motion sensor alarms, and get to know your neighbors.

“That’s so you might have an idea who may or may not belong in the neighborhood,” she adds. “And don’t assume that someone else called 911,” says Mannix. “Call it anyway.”

Keeping valuables out of sight is a good idea. One recent investigation revealed that the money in a store was left in the cash drawer, clearly visible.

“Captain Mannix has been coming to our meetings,” says Alex Feldman, the president of the Marina Merchants Association. “She agrees with our effort to push for more cameras on the street. I notice that Oakland has been getting robbery convictions because of an increased number of cameras. It’s easier to build a case with evidence.”

Feldman says he has added cameras at his store, San Francisco Optics. He has also had some success by installing an anti-break film over the windows.

“We were burglarized twice before I got the cameras and made the glass tougher to break,” he says. “These criminals are professionals. They’re looking for easy targets. If anyone bangs on the windows, the alarm goes off. People need audible alarms.”

Investing a few hundred dollars for lighting and alarms can pay off. Feldman says a break-in can cost the business owner thousands.

Feldman has invited a security advisor to the next meeting of the Marina Merchants Association. That will be held at The Republic restaurant (Lombard and Scott) on Monday, May 9, at 6 p.m.

Having a beat cop on Chestnut Street has also paid off.

“Officer Matt Faliano has been incredible,” Feldman says. “He is totally involved in the neighborhood.”

Mannix suggests that residents also take advantage of San Francisco SAFE (www.sfsafe.org), the nonprofit arm of the SFPD that provides police/community updates, crime-fighting tips, information about neighborhood meetings, and so on.

Feldman adds, “We have to start taking responsibility for ourselves.”