The incident occurred during All Time Low’s set.  According to an Arlington police spokeswoman, an off-duty officer working security responded to a request to help near the stage where a scuffle broke out, presumably when two dozen kids started to fight over a hat.

“The cause of the altercation appeared to have been because the band had been throwing articles of clothing into the crowd and fans were rushing to the stage and tussling over those items,” the representative said, according to the Fort Worth Star-Telegram.

The officer commanded the teenagers to stop the increasingly violent scuffle, then saw a teen on the ground who could possibly get injured.

“Near the teen on the ground, the Arlington officer commanded one young man holding a baseball cap that had been thrown into the crowd to release it, which he refused to do.”

The officer pepper-sprayed the concertgoer, who was later treated.  So were those nearby who were affected by the cast-off spray.

A use-of-force review is expected, the spokeswoman said.

Meanwhile, a concertgoer has posted a camera-phone video of the event.  The video is shaky, but the explicit language is very clear.  All Time Low condemns the action from the stage.