Many RodeoHouston fans say they were convinced all along that what they heard on Wednesday night were gunshots.
Two "pops" captured at the RodeoHouston fairgrounds by cell phone video were later broadcast on social media.
Witnesses claim the pops were gunshots.
"Somebody yelled, 'Run! Run! He's got a gun! He's shooting!'" eyewitness Faith Shoeneman said. "So we were like, closest exit, right here, so we ran out the exit."
Shoeneman left the concert portion of Wednesday night's RodeoHouston performance shortly after it began. She says they had just made it outside when they heard what she describes as two gunshots.
The woman and her friends began to panic amid a chaotic crowd which also was responding to the rush for the exit.
"This car had both of its doors open," Shoeneman said. "Somebody yelled, 'It's him! It's him! He's coming! Run!"
Shoeneman said she is not surprised a weapon may have gotten through security on Wednesday night.
"The person behind us, I turned around, because I heard the metal detector go off," Shoeneman said. "And (the security guards) said go on. They said, 'Just keep going.'"