Over three weeks after a San Francisco cab driver was assaulted and robbed, police have apparently had no luck in identifying the four suspects in the attack. So on Thursday, they released dashcam video of the assault, in hopes that a member of the public might step forward with information on the violent thieves.

According to San Francisco Police Department spokesperson Officer Carlos Manfredi, the assault took place on August 2 (at 4 a.m., ABC 7 reports, while CBS 5 says 4:30). A 41-year-old male cab driver picked up two men and two women at Market and Mason Streets, passengers who said first that they wanted to go to a location on Third Street, then to Texas and 25th Streets in Potrero Hill.

When they arrived at the final stop, Manfredi tells the Chron, “One of them told the driver, ‘I don’t have my money. It’s in the house,’” handing the driver his cell phone as ostensible collateral as he purportedly went to get the driver's payment.

But when he returned, it wasn't with cash, police say, it was with a stun gun, which he used on the driver's neck.

As you can see in the video (the cab driver's face is the one that's blurred out, at his request), the driver tried to climb into the passenger seat to escape the assault, but a second former passenger-turned-suspect opened the door and started punching the driver before pulling him out of the taxi.

The suspects rifled through the taxi and took the driver's backpack, phone, and wallet, as the driver fled the scene on foot "for his own survival," Manfredi says.

“We were able to recover the cab,” SFPD spokesperson Officer Grace Gatpandan told CBS 5, saying that the driver is still recovering at home.

All four suspects, two of whom are clearly visible in the video, remain at large according to the SFPD. If you recognize them or know anything about this crime, you're asked to contact SFPD's Anonymous Tip Line at 415-575-4444 or to text a tip to TIP411 with SFPD at the beginning of the message.