CHICAGO (CBS) — Mayor Rahm Emanuel refused to comment Wednesday on reports a possible suspect in the Boston Marathon bombings has been identified and an arrest is imminent, but he is talking about how surveillance cameras aided the investigation.

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CBS News has confirmed authorities have identified a man seen on surveillance video near the site of the attack, and they want to speak to the man, either as a witness or as a possible suspect.

The man sought as a possible suspect is a white male, wearing white baseball cap on backwards, a gray hoodie and a black jacket, according to CBS News. He is 6 feet or 6-feet-2-inches tall with a medium build.

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WBBM Newsradio Political Editor Craig Dellimore reports surveillance video of the scene of the explosions at the Boston Marathon on Monday has been key in the investigation.

Emanuel noted Chicago has thousands of surveillance cameras, both public and private, that can be accessed through the city’s 911 Center in times of need.

“I will say, as I always have, because we have continued to put cameras throughout the city for security … purposes, they serve an important function for the city in providing the type of safety on a day-to-day basis – not just for big events like a marathon, but day-to-day purposes,” he said.

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The city’s aggressive use of camera technology began under former Mayor Richard M. Daley and has continued under the Emanuel administration.