>> RELATED: #GarlandShooting: Latest photos, videos from the scene in Texas

The contest, sponsored by the American Freedom Defense Initiative, a New York-based group that once fought to keep a mosque from being built near the World Trade Center, offered $10,000 to the winner. The event was being broadcasted live on YouTube.

http://youtu.be/v52q0Z_nSEM

SWAT members were already on scene for the art event, according to WFAA.

The Associated Press contributed to this report.