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TAMPA — More than 80 people have been arrested as part of a months-long human trafficking sting, Hillsborough County Sheriff Chad Chronister announced Monday.

Of the 85 arrests made during the investigation, though, only one person was arrested on a sex trafficking charge.

Most people arrested during the Sheriff's Office sweep face prostitution-related charges. Almost 40 people are charged with offering to commit prostitution. Just over 30 are charged with soliciting another to commit prostitution.

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The undercover investigation started Jan. 1 and was called "Operation Trade Secrets." The sting focused on hotels, motels, spas, massage parlors, strip clubs, adult bookstores and sex trade activities in Hillsborough County, Chronister said.

The Sheriff's Office targeted "johns," Chronister said, with undercover deputies soliciting for sex. But about half of the people arrested were women on charges of offering to commit prostitution.

"The only way to get proof of victims of human trafficking is to do an operation like this," Chronister said during a news conference Monday. "You don't know who's there on their own free will … and who's being forced to have sex. It's probably one of the biggest challenges of interviewing these individuals.

"I believe the only way we're going to combat human trafficking is by targeting the desire. By reducing the desire to those individuals who are seeking to have sex for profit."

People were arrested in Brandon, Gibsonton, Ruskin, Seffner and Tampa during the sting. Some face additional charges unrelated to human trafficking or prostitution, including possession of a controlled substance, lewd and lascivious behavior, possession of child pornography, practicing massage without a license and child neglect.

Chronister said the efforts behind "Operation Trade Secrets" will continue. Monday's announcement was just a "progress report," he said.

The only person charged with human trafficking in the investigation is Marcell Walsh, 40, of Tampa. Walsh was arrested on April 18. A 24-year-old woman he was with at an Embassy Suites hotel in Tampa at 10220 Palm River Road told detectives Walsh was forcing her into prostitution, the Sheriff's Office said. The woman was not charged and was referred to the Salvation Army to receive services and counseling.

In the future, Chronister said he hopes former prostitutes employed by a nonprofit called Created Tampa work with the Sheriff's Office by encouraging human trafficking victims to come forward.

Created Tampa is a Christian organization "committed to the restoration of vulnerable women involved in the sex industry to an understanding of their value, beauty, and destiny in Jesus Christ," according to its website.

The nonprofit did not immediately answer a phone message requesting comment Monday.

Florida last year had the third-most calls to the National Human Trafficking Hotline.

Human trafficking is a particular concern for Tampa as the city prepares to host Super Bowl LV in 2021. The FBI netted 169 arrests in a sex trafficking sting around Atlanta during Super Bowl LIII. Of those arrests, 26 were sex traffickers.

In February, the Greater Tampa Chamber of Commerce organized a summit to enlist local businesses in the fight against sex trafficking and labor trafficking.

Contact Sam Ogozalek at sogozalek@tampabay.com or (813) 226-3430. Follow @SamOgozalek.