Rachel Maddow talks with Denver police spokesperson Raquel Lopez about the details known so far about a gun shot fired at the Obama campaign headquarters in Denver, Colorado.

Denver police were looking for a person who shot at a campaign office for President Barack Obama on Friday, NBC station KUSA reported.

Police say there were people inside the office at the time of the 3 p.m. shooting, but no one was hit.

A single bullet struck the office and broke the window, Detective Raquel Lopez, Denver police spokesperson, told NBC News. But detectives could not confirm that the shot was fired with the intent to hit the office.

Detectives were still investigating the intent of the shot. They were looking into the possibility the shot was fired from a vehicle.

Read more at 9news.com, KUSA's website

Police were reviewing surveillance video for possible leads, KUSA reported. Investigators said they have a "vehicle of interest" and are interviewing witnesses.

A campaign official confirmed the incident but referred questions to the Denver police.

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