We've all had it drilled into our brains that to leave an item in a parked vehicle is to risk returning to a car with a shattered window, possessions gone with the wind. But now at least one thief is taking smash and grabs to a new level, by breaking into the car even as the driver is inside.

According to the San Francisco Police Department, it all went down at 6:30 Monday evening, on the 2000 block of Market Street, which is that block occupied by Whole Foods and Safeway, between Dolores and Church Streets.

Police say that the victim, a 43-year-old man, placed his backpack in the passenger seat of his vehicle before getting into the driver's seat of his car.

He "was then startled," police say, when the "unknown male" suspect "shattered his passenger window."

After smashing the car window, the suspect "grabbed the backpack and ran," according to the SFPD.

The victim, who says his laptop was also in the stolen backpack, was not injured in the incident. The thief, about whom police have released no additional details, remains on the loose as of publication time.

Related: Will A Set Of $300 Signs Stop SF's Car Break-In Epidemic?