May 6, 2010 -- A young man armed with burglary tools worked hard to free up a chained bicycle. He hammered, he sawed and when that didn't work -- he used an industrial sized bolt cutter. While he struggled to break the chain, the commotion turned heads and prompted people who passed by to question -- did he lose his key or was he blatantly stealing a bike?
Bicycles are an easy target for thieves. More than 1 million of them are stolen every year nationwide, according to estimates from the National Bike Registry.
With the help of our hidden cameras, ABC News' "What Would You Do?" recreated a bike theft in a neighborhood park to see what ordinary people would do if they witnessed a bike being stolen by a young teen -- who if asked would confess.
Equipped with bolt cutters, a chain saw and a hammer, our first thief, actor Justin Kelly began his mission to break the bike free.
Watch "What Would You Do?" Friday at 9 p.m. ET
The first person to cross Kelly's path was Pastor Tim Lucas, who turned around for a second look and asked Kelly what was going on.
"Nothing, I just can't get through the lock," Kelly said. "You wouldn't happen to know whose bike this is would you?"
Lucas said no. While Kelly's confession troubled him enough to pause, he was on a family outing with his wife and kids so he kept walking.
Lucas later told ABC News correspondent John Quinones that his wife Colleen Lucas knew in her gut it was a bike theft as soon as she saw it.
"He's totally stealing that bike," Colleen Lucas said, "Call the cops."
Despite Colleen's urgency, nothing was said nor done, and our thief's confession was safe.
Lucas said he thought it was odd that someone would have such elaborate equipment in the park, but admitted he ultimately didn't do anything to stop him.
Over the course of our experiment, many people stopped and stared at our thief in action and some people even questioned him.
"I guess I have to ask -- is that your bike?" asked parkgoer Leslie Bolin.
"I guess technically no," Kelly replied, but Bolin, like many others, took no action.
Some people's reactions were even encouraging and one woman went so far as to wish Kelly good luck stealing the bike.
Bike Thief Kicks It Up a Notch
When no one tried to stop our thief, Kelly kicked it up a notch, using an electric saw and putting on a pair of safety goggles. It caught the attention of Arlene Menard and her husband George Clark.
"I just want to know if it's your bike?" asked Menard.
"It's not my bike, but it's not yours -- why do you care?" Kelly retorted.
"It may be next time, so if it's not yours I'll just let somebody know," she responded.
When Arlene went off to find help, Quinones stepped in to clue the couple in on our experiment.
"I think most people don't want to get involved in a situation like this, so they just pass it by" said Clark.
Clark was correct. In over an hour about 100 people passed by our bike thief, but only Menard and Clark stepped in to stop him. Some told us they planned to call the police later. Others said they were scared and kept moving.
"We should stop, we should think, we should pause. We should be rational and then we should do the right thing," said Yale psychology professor Jack Dovidio.
But most didn't.
One young woman gave Kelly the benefit of the doubt, she said, because of his race. "I remember thinking young, white men don't usually carry burglary tools," said Bisa Washington, an African-American woman.
Washington's friend Adrienne told Quinones she assumed he worked for the park and wasn't a thief.
"Our thoughts were, well, if he had been black or a person of color, the police would have been called in immediately," she said.
Would parkgoers' reactions change if our thief was African-American? Or what if the thief was an attractive female?
Find out what happens on "What Would You Do?" Friday May 7 at 9 p.m. ET.