One of the complications for the SWAT team at the scene of the shooting is the concern of the shooter's location and the safety of any officers inside. At one point during the shooting, two police officers were barricaded on the second floor of the building, according to two law enforcement sources. It's unclear if the officers remain barricaded.  According to one of the sources, a suspect appeared at one point to be on the first floor and was firing through walls.

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