While companies like Tesla and Uber are selling the dream of autonomous cars, many are worried about its practical implementation and the lack of infrastructure for such technology to come to life.

This is the reason that when an autonomous vehicle gets crashed or is involved in an accident, there’s extra scrutiny for it. In line with this, US auto safety agency has said that it will investigate a 12th Tesla crash that may be tied to the vehicle’s advanced Autopilot driver assistance system.

In this incident that happened last week, a Tesla Model 3 car rear-ended a parked police car at Interstate 95 in Norwalk, Connecticut. It has been confirmed that the National Highway Traffic Safety Administration (NHTSA) special crash investigation program will investigate this crash.

The Tesla driver said the vehicle was on Autopilot and he was checking on his dog in the back seat when the accident happened. The driver was issued a misdemeanor summons for reckless driving and no one involved was seriously injured.

Autopilot had been engaged in at least three Tesla vehicles that were involved in fatal crashes in the United States since 2016. The agency’s special crash investigation team has inspected 12 crashes involving Tesla vehicles where it was believed that Autopilot was engaged at the time of the incident.

Tesla and the NHTSA both have advised drivers that they must keep their hands on the steering wheel and pay attention at all times even when using Autopilot. The company says Autopilot “enables your car to steer, accelerate and brake automatically within its lane,” but does not make the vehicle autonomous.

This incident will give further voice to a lobby of people that are suggesting Tesla should disable Autopilot until the company installs new safeguards to prevent drivers from evading system limits that could let them fall asleep.