Armed man arrested during St. Pete protests after throwing 'projectile' at chief, police say

After a day of trying to convince demonstrators that unity was the key to moving forward, St. Petersburg police brought out the riot gear and lined up to block protesters outside their headquarters.

One person in the crowd was taken into custody after allegedly throwing something at Police Chief Anthony Holloway and another officer. 

Police say they asked a group to move onto the sidewalk along 1st Ave. traffic could pass. 

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That's when a demonstrator threw a "projectile."

After detaining the suspect, police say they found he was carrying a loaded gun in his waistband.