Chicago Police Superintendent Garry McCarthy says it was a miscommunication when his officers put on gas masks during NATO summit protests.
McCarthy said Monday that radio traffic during Sunday's major NATO protest described one protester in the crowd wearing a gas mask.
McCarthy said the message got repeated and officers thought it was an order to prepare. But McCarthy, who was on the scene, said he was not considering using pepper spray and told officers to take them off.
McCarthy says he never gave an order to use gas and he gave everyone an all clear.
Chicago police and protesters scuffled after a planned march and rally near the site of the NATO summit on Sunday.