The rally was hosted by Traffik 911, an organization that raises awareness for sexual slavery.
Clint Dunn said while he hates to think such a horrible thing could happen to his daughter, he's not ruling it out.
"I've been scared of that since the beginning. That's why I went to Mexico twice handing out flyers," said Dunn.
He said the thought of his daughter being forced into sexual slavery breaks his heart.
"There's no words to describe the feeling. It's just so scary," Dunn said.
Dunn said working with Traffik 911 has showed him human trafficking doesn't just happen in third world countries.
"It's everywhere, places you wouldn't expect. It's an epidemic in America," he said.
Hailey was sold into sexual slavery
Dunn hung banners with Hailey's picture and handed out fliers at the event. He said he wants to keep his daughter's name out there.