DENVER (CBS4) – Denver police are hoping the public can help them identify a man suspected of sexually assaulting a woman on the 16th Street Mall last month.

“This is highly unusual, but also highly concerning,” Sonny Jackson, a spokesperson for the Denver Police Department said.

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The assault happened at approximately 10 p.m. on Sept. 19 in the 500 block of the outdoor mall. Police said the woman was looking for her cousin when the suspect approached her offering help.

“This is a situation where this individual looked like he was going to be helpful and he wasn’t,” Jackson said. “He drug her into an area and then sexually assaulted her.”

Authorities described the suspect as a white or possibly Hispanic man who is about 5-feet-9 with a skinny build. He is believed to be about 25 years old with short hair.

“He might go by the name Frank,” Jackson said.

The mile-long mall has struggled with crime for years, which is part of the reason why the city of Denver and Downtown Denver Partnership spent some of the summer surveying visitors about their experience on 16th Street.

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“We’re using all of that information to look at the vision for the place,” Tami Door, President & CEO of Denver Downtown Partnership, told CBS4 in July. “How do we turn this space into an amazing place?”

CBS4 spoke with some women visiting the pedestrian mall who say though they feel safe, they keep an eye out for anything suspicious while there.

“I’m more prone to come here during the day than I am at night,” Kathryn Knowlton said.

Another visitor said the recent crime is scary, but it won’t prevent her from coming to the 16th Street Mall.

“It’s overwhelming, but you can’t let that stop you from doing what you need to do,” Megan Edelson said.

Police are asking anyone who may recognize the suspect or have information about the crime to call Metro Denver CrimeStoppers: 720-913-7867.

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Kelly Werthmann joined the CBS4 team in 2012 as the morning reporter, covering national stories like the Aurora Theater Shooting and devastating Colorado wildfires. She now reports for CBS4 News at 10 and is always open to story ideas. Connect with her on Facebook or Twitter @KellyCBS4.