SAN ANTONIO -

A 23-year-old woman arrested in connection with a child sex trafficking case that spanned from Wisconsin to Texas is in the Bexar County Jail.

According to the arrest warrant affidavit, the case against Gionna Smith took more than a year to investigate.

The National Center for Missing and Exploited Children reported the case involving a 16-year-old Austin teenager in December 2012 to the Texas Attorney General's Office.

The affidavit alleges Smith had customers meet the young girl at a hotel in San Antonio “for the purpose of engaging in continued acts of prostitution and causing the victim to be a repeated victim of sexual assault.”

“It’s a horrifying case and unfortunately, it’s happening far too often,” said Tranette Ledford, spokeswoman for the Heidi Search Center in San Antonio.

Ledford said many families who contact the center about children who have run away often fear their sons or daughters will be forced into the sex trade.

The affidavit describes how the girl first met with Smith and a unidentified man at an Austin hotel, then remained with the pair for more than two weeks.

Investigators said the teenager told them from that point she had sexual relations with 100 to 200 men from December 2012 to January 2013.

Ledford said for the traffickers, “That’s nothing. They’re in it for the money and girls are lucky to get out alive.”

But like many in her situation, investigators said the girl was never paid; the sex trafficker kept the money.

They also said the girl told a friend she "engaged in sex acts in every city along the way.”

Susan Reed, Bexar County district attorney, said sex trafficking is a “traveling crime, going city to city and state to state.”

A member of the Attorney General’s Task Force on Human Trafficking Prevention Task, Reed said she is not surprised it took this long to make an arrest.

She said often the victims will not cooperate.

“They become hardened. They don’t have an easy time opening up about what has happened to them,” Reed said.

According to the affidavit, the pair drove the girl to Milwaukee, Wis., where she was spotted by police on the street.

Officers cross referenced information from the Texas Attorney General's office and found Smith in a nearby home, then took her into custody.