CHICAGO (CBS) — A man stood charged Saturday with running a prostitution operation out of his Bridgeport neighborhood apartment.

The Cook County Sheriff’s office said Peter Zhang, 42, was arrested Friday afternoon after a search warrant was executed in his apartment in the 500 block of West 26th Street.

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The Sheriff’s police had received a tip on Tuesday from the National Human Trafficking Hotline that multiple women were being trafficked from the building where Zhang lives. The tip included cellphone numbers that Zhang is accused of using to book appointments for the trafficking victims, Sheriff’s police said.

Sheriff’s Police Special Victims Unit investigators matched the phone numbers up to those found on various websites that advertised escort service, and saw activity that looked like prostitution happening in the building on the same day, police said.

Investigators saw two men walk into the building and leave shortly afterward. They stopped one of the man, who admitted that he had paid for sex with one of the trafficking victims in the building after calling a number on an adult website, police said.

On Wednesday, an undercover SVU investigator started trying to make a “date” with one of the trafficking victims, and on Thursday, the investigator got a reply. The investigator met the victim, a 21-year-old woman, who agreed to sex for $200, police said.

At that point, the investigator sent other sheriff’s officers in.

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Investigators learned Zhang lived in an apartment on the same floor where the undercover investigator had met the young woman. They knocked and no one answered, so they got a search warrant and went inside – finding Zhang and another trafficking victim, police said.

Investigators found $3,000 in cash, about 20 cellphones used to arrange “dates” for the victims, contracts between Zhang and the victims, hundreds of condoms and boxes of lubricant, and a surveillance system that monitored the outside of the building and the apartment where the undercover investigator went, police said.

Investigators also found text messages from Zhang to the woman the undercover investigator met, warning her that investigators were outside and she was not to say anything, police said.

The women were offered social services by the Sheriff’s office and were not charged. The first agreed to receive social services, while the second declined – but was given information on how to obtain help if she changes her mind, police said.

Meanwhile, Zhang was charged with the Class 3 felony of promoting prostitution within 1,000 feet of a school. He was given a $100,000 bond and ordered to surrender his passport on Saturday, police said.

The Sheriff’s office urges anyone who is a victim of trafficking, or has information about someone who is, to call the Sheriff’s Human Trafficking Hotline at (312) 718-4451 or contact the National Human Trafficking Hotline by calling (888) 373-7888 or texting HELP” or “INFO” to SMS 233733.

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