A surveillance camera outside the office of WCG, a global communications company at 60 Francisco St., captured footage of the thief in action, and the company posted the video to its YouTube page Tuesday after two of its workers thwarted the theft on July 20.
The video shows a man with a shaved head wearing a blue shirt, shorts and a backpack snip a lock that secured a bicycle on a rack in the brightly lit courtyard outside the building.
Kristen Bell, a creative associate at the company, said her female coworker was timidly observing the events unfold through a window.
The coworker hesitated but said that someone was stealing a bike. Bell, thinking the bike was hers, bolted through a door to the courtyard.
"I just saw someone riding off," Bell said. "I just got up and ran out the door."
Because the bicycle actually belonged to a "rather tall" female intern at the company, Bell said, its seat post was too high for the thief to ride off quickly or comfortably.
The video shows the thief fumbling, and just as he finally gets on the bike, Bell and a male coworker come bursting out of the office door. Bell dives for the front tire, blocking the thief's way and causing him to topple off the bike.
The thief scoops up his belongings and casually ambles away. Although Bell said she and the male coworker could have chased him down, she thought twice.
"I realized that it was probably a bad idea," Bell said. "I could hear my mom's voice saying 'This guy's got a knife.'"
It turned out to be a wise decision, she said, because when building security guards tried to confront the man, he allegedly pulled a knife on them.
"I think we did a pretty good job of avoiding conflict," Bell said."
It is rare that a stolen bike is recovered, but it is even less common that the victim of the crime is avenged.
In this case, both happened. Bell said that before trying to steal the WCG intern's bike, the thief apparently had chained his own bicycle to a sign outside the building. During the courtyard scuffle, he dropped the key to his lock.
The key ended up in the hands of building security guards, who happened to notice the improperly locked bicycle. They unlocked the bike and confiscated it, Bell said.
"Whoever's missing that bike can claim it within 30 days," Bell said.
Although the bike thief was unsuccessful in his theft attempt, there have been several other bikes stolen from the same rack in recent years, Bell said.
In this case, the intern's bicycle was tethered to the rack with only a cable lock, which can be easily cut, as the thief did.
But even taking measures to better secure two-wheeled property may be for naught at this location, Bell said, because the rack itself has been tampered with in the past.
"It's just never really felt like a good place to keep our bikes even though it's in broad daylight and there's security walking around," she said.