CHICAGO (CBS)–There are more than 5,000 active police investigations in Illinois hinged on pending DNA results, and lawmakers are demanding the state take action to address the backlog.

The call for action follows a CBS 2 report from investigative reporter Pam Zekman that revealed 50 unsolved strangulation cases that could be the work of a serial killer.

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Six of more than 50 women who were strangled in Chicago since 2001, in what the Murder Accountability Project believes is a case of a serial killer on the loose. (Credit: CBS)

At an Illinois Senate hearing loved ones of some of the victims were vocal about their need for justice.

Among them is Ricardo Holyfield. His cousin Renee was the most recent murder victim in 50 cases CBS 2 highlighted in a report last month.

“There’s somebody out here killing people, (but) they’re not catching them (and) we need help,” Holyfield said at a hearing Monday.

His cousin’s body was found in a garbage container last September. Her murder is part of a pattern of unsolved cases dating back to 2001, according to Thomas Hargrove, the founder of the Murder Accountability Project, a nonprofit organization which disseminates information about unsolved murders.

“We honestly don’t understand why it’s not already known that some of these are connected killings,” Hargrove said.

Read more about the serial murders: 

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A Serial Killer In Chicago? Investigations Delayed By Backlogs In Analyzing DNA

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Hargrove’s research has successfully identified patterns in other cities, and he believes that, here in Chicago, clusters of killings also show a pattern.

In all the disturbing crimes he believes could be connected, the victims were strangled and their bodies were dumped outdoors.

“I think its a problem that there is a backlog of thousands of DNA test kits, rape kits–whatever the samples are they should be processed and prosecuted.”

At the March 25 hearing, Illinois State Police said they hope new measures put in place to reduce the backlog–like increased staffing and the addition of new technology–will help deal with a backlog of 5,121 cases pending DNA testing. The backlog includes 2,298 sexual assaults and 658 murder cases.

“We are working vigorously and our hope is that in the next 18 to 24 months we see a measurable impact on the DNA backlog,” said Mathew Davis of Illinois State Police.

State Senator Patricia Van Pelt, who chaired the hearing, said the new staffing levels and technology fell short of the resources the state needs to catch up with the demand in DNA testing.

“That’s entirely too long, and so I’m looking for solutions and will work with them to find solutions,” Van Pelt said.

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Chicago Police Superintendent Eddie Johnson has now ordered a review of all 51 strangulation cases in Chicago to see if there were DNA samples taken at the crime scenes and whether those samples were tested.