GREENSBORO, N.C.-- Investigators in Boston are reviewing hours and hours of video taken from spectators' cell phones and store's surveillance cameras, in hopes of identifying the person or people responsible for the marathon bombings.
Downtown Greensboro has dozens of cameras watching over the streets, sidewalks, parking garages and even on city buses.Many cameras are stationary and others are motion cameras.
Business owners like Trevor Austin of Stumble Stilskins, have their own cameras.
"You know what you can to prevent things from happening but you don't know what other people are going to do," Austin says.
When an incident occurs, one of the first things investigators look at is surveillance video.
"We've had cases where the person says, 'no I didn't have a weapon' and we go back and the video shows clearly they had a weapon," says Col. Randy Powers with the Guilford County Sheriff's Office.
Guilford County Sheriffs are seeing more and more homeowners installing cameras around their homes.
"It's probably hard to travel four or five miles, and not come across a camera somewhere," says Col. Powers.
Some of Greensboro's cameras record, others feed back footage to a monitoring area.