Security robots are being used to patrol the streets of Silicon Valley.

The startup behind the fleet, Knightscope, has raised $25 million in funding.

Knightscope drew sharp criticism in 2017 after a robot was used to prevent homeless people from setting up camp in San Francisco.

The startup behind the autonomous, crime-fighting robots used to patrol the streets of Silicon Valley has received new financing to create its RoboCop fleet of the future.

On Tuesday, Knightscope announced over $25 million in new funding from Konica Minolta, Bright Success Capital, and 5,000 other investors through crowdfunding website SeedInvest. This brings the company's total funding to $39 million.

Founded in 2013, Knightscope makes intelligent robots that patrol malls, parking lots, and corporate campuses for tech companies like Microsoft and Juniper Networks. The robots don't fight humans; they use an array of lasers, cameras, thermal sensors, and GPS to detect criminal activity and alert the authorities.

Their goal is to give human security guards "superhuman" eyes and ears, according to Bill Santana Li, CEO of Knightscope, who spoke with Business Insider in 2017.

Knightscope has been surrounded by controversy since its founding.

In December, the San Francisco SPCA, an animal welfare group, put a security robot to work outside its facilities in order to prevent homeless people from setting up camps along the sidewalks. The group said the number of camps dwindled and there were fewer car break-ins.

But the move drew sharp criticism from the National Law Center on Homelessness and Poverty and others who said the SF SPCA showed "a lack of compassion" for its homeless neighbors.

The SF SPCA pulled the robot from the streets in December. Jennifer Scarlett, the group's president, said in a statement that the SF SPCA received hundreds of messages "inciting violence and vandalism" against the facility and "encouraging people to take retribution."

In 2016, a Knightscope robot allegedly ran over a toddler's foot while monitoring a mall in Palo Alto. The boy's foot swelled and he got a scrape on his leg, though he was fine otherwise, ABC7 News reported. A small number of parents took to social media to rail against the company.

Knightscope rents out the robots for $7 an hour — less than a security guard's hourly wage. The company has 50 robots deployed in 14 states, though it would not disclose revenue figures.