Tesla, as well as Elon Musk’s “Autopilot” feature, will be investigated by the National Highway Traffic Safety Administration (NHTSA) after a 2018 Tesla Model 3 rear-ended a police car earlier this month in Connecticut, the twelfth recent Autopilot-related crash investigated by the agency.

The NHTSA said on Friday that it will be investigating a December 7 Tesla crash that may be in connection with the vehicle’s Autopilot driver assistance system, according to a report by Reuters.

The automotive company’s latest incident involved a 2018 Tesla Model 3 that rear-ended a police cruiser in Norwalk, Connecticut, making it the twelfth Tesla crash suspected to be related to Autopilot to be inspected by the U.S. auto safety agency.

The report added that Autopilot has been engaged during at least three fatal Tesla crashes in the U.S. since 2016, noting, however, that the agency had ruled out Autopilot as a factor for one of the crashes.

Tesla and the NHTSA both advise drivers that they must keep their hands on the steering wheel and pay attention at all times while using Autopilot, according to a report by the New York Times, which added that Tesla warns drivers that while Autopilot “enables your car to steer, accelerate and brake automatically within its lane,” it does not make the vehicle autonomous.

The Times added that some drivers claim that they are able to keep their hands off the wheel for an extended period of time while using the Autopilot function.

As for the incident involving Tesla’s December 7 crash, the driver said his vehicle was on Autopilot while he checked on his dog in the back seat prior to the Tesla hitting a police car that was parked while an officer waited for a tow truck to assist a motorist.

The report added that no one was seriously injured, but the driver was issued a misdemeanor summons for reckless driving.

“This crash could’ve been avoided,” said Senator Richard Blumenthal (D-CT). “While autonomous vehicles are an exciting development, the tech is simply not ready to be deployed safely. Congress must act to protect the public from these vehicles until their safety can be assured.”

You can follow Alana Mastrangelo on Twitter at @ARmastrangelo, and on Instagram.