CHICAGO (WLS) -- It's been 15 years since the unsolved mass murder at the Tinley Park Lane Bryant store. Five women were shot dead on a quiet Saturday morning in the suburban clothing store.
For 15 years, authorities have been searching for clues to crack the unsolved murder mystery. The I-Team has long reported that police were also listening for a break in the case from an audio recording of the killer.
Investigators hope future technology could someday solve the cold case.
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"I think about her every day. But when you say 15 years, I'm shocked," Michele Talos said.
Talos' sister Jennifer Bishop, along with Carrie Chiuso, Connie Woolfolk, Sarah Szafranski and Rhoda McFarland were tied up and shot to death in the back of the store in Tinley Park. A sixth woman was also shot that day. She survived.
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Store manager Rhoda McFarland called police during the crime.
"At this point, you know, it's up to God and the detectives," said Maurice Hamilton, brother of Rhoda McFarland.
Former U.S. Marshals Service Supervisory Inspector Ed Farrell has worked on the investigation.
"We were tangentially involved through what I would call identifying the electronic footprint of those involved in the crime. We were contacted by the South Suburban Major Crimes Task Force, requesting assistance and just trying to identify people that might have been in the area who could have perpetrated this crime," said Farrell, who is the current owner of Silver Star Protection Group.
That high tech evidence could eventually help solve the case.
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"The information is there. Now we're just trying to reverse engineer with information who that person was," Farrell said.
The killer claimed he was a delivery man. His voice is heard on the 911 call. The I-Team has learned investigators have more audio of the suspect than has been released to the public.
"There are auditory ways to try to match people and we don't know what the future brings in that technology. So, it's a great piece of evidence as technology advances. We have his voice; the whole tape hasn't been disclosed. There's more than that just one small segment," Farrell told the I-Team.
Click here for a timeline of the Lane Bryant murders and investigation
He said surveillance video shows the killer likely didn't act alone.
"There was one camera on a Target store that was able to capture some footage of the front of the store, and right around the time of the shootings, two vehicles pulled up: an SUV and a sedan," Farrell explained. "And it's believed, one of the theories is, he engaged in shooting, he had accomplices, they came out front and they sped away. You know, because they pulled up simultaneously and left in the same amount of time. And little known is there was an officer in the Target parking lot when they went down. And when the 911 call came through, they dispatched the officer from Target, so he was only a minute or two minutes away. So, in that small window somehow he was able to get out of the store."
After 15 years of pain, 15 years without answers, family members of the victims have this message to share with the killer.
"I would really like to know why, when you took my sister away from me, and I'm sure this is the same for all the other families, but you affected way more lives than just their immediate lives," Talos said.
"You thought you were man enough to go into the store, kill five women and injure a sixth. Be man enough to turn yourself in," said Hamilton.
Tinley Park police decided they would not participate this year in a story about the unsolved mass murder. A brief written statement on the village website quotes police Chief Matthew Walsh as saying "Someone out there knows something." But Walsh was unwilling to say that on camera.
The public is asked to contact police if they have information about the case.