The ITeam started looking into this after a killing last summer at a Gold Coast boutique hotel, attracting attention around the world-until it was discovered the victim was a prostitute.
Brianna at the Whitehall Hotel; Carolyn next to the Chicago River; Leslie in an empty West Side building; they all had three things in common.
They worked as prostitutes. They were murdered. They had parents.
"Sometimes I didn't know where she was," said Lutelda Hudson, victim's mother.
For a mother, the one thing worse than not being able to find your child is finding them on the wrong side of the police tape.
Consider Lutelda Hudson's daughter. Off her meds for a bipolar condition and on the street working as a prostitute. Dead at age 29, she was one of four women with prostitution records found strangled, in abandoned buildings, during a two year period.
"Aug 2008 to 2010 there was a pattern in a series of women being killed in the Roseland neighborhood," said Anita Alvarez, Cook County State's Attorney.
Alvarez charged Michael Johnson.
"He is charged with six cases all together; four are murders and two are attempted murders," Alvarez said. "What we've seen are some eerie patterns where victims are found in an abandoned house, naked and strangled...it's sad because I think these murders happen more frequently than the general public thinks."
Chicago police officials don't know how many of their unsolved murders involve prostitutes, telling the ITeam it's not a statistic kept on reports, though case investigators would have such information.
Police say they pursue prostitute murders as vigorously as any other but admit they are often harder to solve.
"When you are talking about a murder for a person who has a high risk lifestyle you may have some reticence in the community...they are in contact with a lot of people, a lot of people they do not know," said Commander Gary Yamashiroya, Chicago Police Department.
It took almost three years to charge 38-year-old career criminal Melvin Fagan. Last month Fagan was accused of a 2009 prostitute murder.
The ITeam has learned authorities have added a new charge against Fagan, alleging he used a screwdriver to force a woman into her own car trunk, drove her around for two days and raped her at different locations.
Many cases are still unsolved.
Consider Carolyn Shranz whose mother recently posted her photo where the body was found in 2008, hoping to rekindle someone's memory.
"Nobody should die like that, no matter what their lifestyle was," said Rebecca Stowers, victim's mother.
"They don't always have a family there that is looking after them and caring for them and so the prostitute is a prime target for the serial killer," said Alvarez.
Stopping prostitute serial killers is one reason Alvarez formed a new task force that targets the trafficking of women and under a new state law, not going after the women, but rather the people who put them out for hire.
"We are talking about kids right here, picked up on the street, many times homeless, forced to get into this line of work they are being abused," said Alvarez.
A mother makes a plea, in her daughter's memory.
"I know that a lot of people don't want to get involved but some things, you need to get involved with, you don't know whose life you might be saving," said Hudson.
In just two years, the state's attorney's task force has charged 60 people with human trafficking. Illinois's human trafficking law is one of only 10 in the U.S. and considered the most comprehensive. National legal groups are hoping our law will be a prototype for other states.
Illinois Safe Children Act:
Cook County States Attorney
Chicago Police Cold Case Unite