"I heard her scream. What I saw was the black male on top of her," Oscar O'Bar said.
The sound of fear pierced the crisp, quiet night air on Crosby Street Monday around 8:00 p.m. in East New York.
It sent O'Bar's heart racing and adrenaline roaring.
"And then I when saw him grab her bag and ran I was like whoa! My first instinct was to chase him," he said.
O'Bar zoomed off after 29 year old Nathaniel Flowers for three blocks. O'Bar didn't see a gun, but neighbors saw the chase and their instincts kicked in too.
Flowers dove over a fence and tried to hide in a backyard. The entire neighborhood now wouldn't let him leave the block.
"He got trapped. Everybody chased him," O'Bar said.
With four sisters, and a handful of-nieces and grand-nieces, O'Bar says it was second nature.
"It's a macho thing, he broke the code against women," he said.
O'Bar, who is currently out of work, says his dream is to get a job as a New York City Sanitation worker.