A Palo Alto toddler was injured last Thursday after his parents claim a security robot at the Stanford Shopping Center knocked him over and then proceeded to run him over. And what’s more, ABC 7 reports that this may not be the first time that the 5-foot-tall, 300-pound autonomous robot has injured a child.

We first learned about the Knightscope K5 last week when it was reported that Uber rents one of the Silicon Valley-manufactured robots to patrol its San Francisco inspection lot. The company that makes the digital rent-a-cop calls it “a new groundbreaking innovation in advanced physical security,” and notes that “[this] technology changes everything and is especially needed as the world continues to become more and more volatile.”

In this case, however, it seems that the robot might be the cause of the volatility, not a response to it.

“The robot hit my son’s head and he fell down facing down on the floor and the robot did not stop and it kept moving forward,” Tiffany Teng explained to the channel. “He was crying like crazy and he never cries.”

Fortunately, 16-month-old Harwin Cheng escaped the baby-on-machine interaction with only a swollen foot a few scrapes, but his parents worry that the K5 could injure other small children. And, in a revelation that makes Thursday’s encounter read like the first inklings of a robot uprising in a science fiction story, we learn that the robot may have struck before. According to Harwin’s parents, a human security guard at the mall told them the robot had had a similar encounter previously with another toddler.

The K5 has been on patrol at the shopping center since 2015, reports The Mercury News, and ABC 7 notes that the center did not return a request for comment. Elon Musk’s Tesla Motors Autopilot uses the same kind of technology.