An autonomous vehicle was apprehended earlier this month by San Francisco police officers, who were startled and confused to find nobody in the driver’s seat, according to footage of the incident. A spokesperson for Cruise, a driverless taxi service, explained to Insider that its car was pulled over on April 1—of all days—for failing to have its headlights on. This was attributed to “human error,” The Guardian reported. As an officer approaches the vehicle’s driver side, according to video that circulated on social media after the traffic stop, a bystander can be heard calling out, “Ain’t nobody in it! This is crazy.” The officer, seemingly perplexed, tries to open the Cruise’s door before walking back to his vehicle. As he does so, the Cruise takes off, going “on the lamb,” as one Twitter user quipped. It drives across an intersection and pulls over again—exactly as it is meant to, according to Cruise. In a tweet from a corporate account, the company explained that “our AV yielded to the police vehicle, then pulled over to the nearest safe location for the traffic stop, as intended.” No citation was issued, according to the company.