"One thing that the robots can do ... is provide a commanding presence. Obviously because of their size, they get a lot of attention. If you can imagine a criminal coming onto a property and seeing these robots roaming around. They don't know what they do, they don't know what they are capable of," Stephens, a former police officer, said. "Criminals don't want to get caught, and the biggest thing you can do to prevent and deter (criminal activity) is provide a commanding presence."

The robots, which operate within a predefined area, are unarmed but their size and appearance will likely make someone think twice before committing a crime, Stephens said.

Mountain View-based company Knightscope, which was founded in response to the deadly shootings at Sandy Hook Elementary School in Newtown, Connecticut, developed the robots. The shiny white bullet-shaped machines gather real-time data through numerous sensors as well as publicly available data from businesses, government and social data feeds and then process the data through a predictive analytics engine, said Stacy Dean Stephens, vice president of marketing and sales. If the robots determine that there is a concern or threat in the area they are patrolling, a real-time alert is sent to the community and authorities through the Knightscope Security Operations Center.

Standing at 5 feet tall and weighing 300 pounds, Knightscope K5 looks like it came straight out of the sci-fi film Stars Wars. But the crime-fighting robot is actually a new breed of security guards roaming Silicon Valley, including at Palo Alto's Stanford Shopping Center as part of a pilot program that ended in June.

Stanford Shopping Center, which is owned by Simon Property Group, participated in the test to try out the Autonomous Data Machines. The program started, coincidentally, on May 4, often referred to as "Star Wars Day." Two robots were deployed at the shopping center to patrol its parking lot and interior space.

"It can also be something more friendly or benign like telling people that the mall is closing and make your last-minute purchases," he added.

The K5 also has broadcast capabilities, so, for example, in an active-shooter situation, the robot can broadcast a message to warn everyone of what's going on, Stephens said.

"If you have someone in an emergency situation, and they need to contact someone in a security operations center, they can push the button on top of the robot to have a two-way conversation," he said.

"There's only so much technology an officer can carry on their belt or on their back, so what we wanted to do was augment that in a way that was never done before, and that is put all kinds of sensors and technology on a fully autonomous robot," Stephens said.

The robots are deployed at different places, including corporate campuses, shopping and data centers, large sporting venues and big-box stores, Stephens said, but the robots are not meant to replace human security guards. They enhance the way security is done today by assisting officers and improving response times, he said.

"When you put (the robots) into public areas like the Stanford Shopping Center, we have to make certain that the public embraces it," he said. "Everyone has been extremely both friendly to the robots but also really enthusiastic about their mission and what they're there for."

But Stephens said the approachable and friendly looking robots (which look similar to Star Wars' R2-D2) have received an overwhelmingly positive response from people who have encountered them. People will come up and interact with the robots -- even give them a hug.

Neither a representative of Simon Property Group nor Stephens would disclose how effective the robots were during their trial, nor whether the shopping center plans to continue their use.

"Most people are unaware that crime has a $1 trillion negative economic impact on the U.S. each year ... and we feel like, if we can cut that in half, we'll be doing something good not only for our local community but also for the entire country," he said.

"It is a security camera. It's no different than when you walk into a store and there is a security camera mounted up on the door sill. This just happens to be a mobile platform for doing so," he said.

For those concerned about the robots threatening individual privacy, Stephens said the company takes privacy very seriously and the technology the company employs is no different than what people encounter every day.

Robots deployed to protect and serve

Mountain View firm's autonomous security robots join fight against crime, including at Stanford Shopping Center