Chris Martinez (CBS News) – A California company has come up with a high-tech way to find out who’s at the door and to keep criminals away.

The Ring Video Doorbells let people see, hear and talk to visitors, even when the homeowner is away. They are already used in more than 300,000 homes and are keeping criminals away in one neighborhood, reports CBS News correspondent Chris Martinez.

False alarms, deliveries, stolen packages, attempted burglaries and even romantic serenades are all being captured by the Ring Video Doorbell.

When visitors press the doorbell — or set off the system’s motion detector — it sends an alert to the homeowner’s smartphone.

Last year, Ring partnered with the LAPD as part of a pilot program to reduce burglaries.

“When someone rings the doorbell, it tells me that someone’s at the door and there we are,” said Robby O’Donnell, one of the program’s participants. She and her husband are survivors of a violent 1980 home invasion.

“You can adjust the sensitivity to have a smaller radius or a narrower focus,” O’Donnell explained. The O’Donnell’s device reaches out to the sidewalk.

“About 30 feet. I can pull it back to five feet,” O’Donnell said.

At the ring of her doorbell, Robbie sees a clear view of her front porch from her phone. Los Angeles police say since the Ring neighborhoods program began, they’ve seen an estimated 55 percent drop in crime.

Since starting the company in 2012, Jamie Siminoff has received nearly $100 million in funding from investors, like British billionaire Richard Branson.

“It brings you into the home no matter where you are,” Siminoff said.

Ring’s devices are powered by traditional electric wiring or battery, but they do require an internet connection.

“The biggest problem is if you’ve got sub-standard Internet, it’s hard to set up,” O’Donnell said.

CNET editor Dan Ackerman warns that like all systems dependent on Wi-Fi, there is room for error.

“You’re seeing a lot of concerns with what we call the Internet of things,” Ackerman said. “The biggest vulnerability really, a lot of this new technology where maybe everything is not fully baked yet – you really have to test all the hardware and software configurations.”

Siminoff hopes that the mysterious voice who answers the door is enough to deter unwanted visitors, whether you’re home or away.

“The motion detector goes off. I say, ‘Why is someone at my door at 3 o’clock? No one is supposed to be there,'” Siminoff said. “I can now say to the person, ‘Can I help you?’ They have no idea where I am.”

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