ABC 7's Leah Hope visited the Illinois State Police Forensic Science Facility. Scientists showed us what they do and why the cases can take months to complete.
The Illinois State Police Crime Lab analyzes thousand of DNA cases every year. Last year scientists analyzed 5,000 DNA cases. A new law will likely increase the demand for DNA testing in sexual assault cases.
On the near West Side of Chicago, scientists work hundreds of cases at the Illinois State Police Forensic Science Center.
Scientists who work the DNA cases have to wear protective clothing and hair coverings so their DNA doesn't contaminate the samples.
A scientist showed us how they handle a rape kit, which would have seven to 10 samples from one victim of sexual assault.
There are three tests to see if semen is found. This test determines if the enzyme for semen is present; it's called an acid phosphotase test, or AP for short.
If there is semen, the forensic investigation continues, ultimately trying to find identify a DNA profile and to identify a suspect.
The work is meticulous and methodical, and it takes time.
Identifying whether or not there is a usable sample can be relatively quick, but the whole process for sexual assault DNA analysis takes on average two months. The state police crime labs already have a backlog of more than 600 DNA cases .
A new law may put more demand on the state's forensic scientists.
"We've been unable to speculate on how many cases we will be receiving, but we know there's a possibility of an increase in the cases we receive," said Master Sgt. Isaiah Vega, Illinois State Police.
Earlier this week, Governor Quinn signed a law that mandates all rape kits be turned over for testing within 10 days. And a report by Human Rights Watch found that currently only 20 percent of rape kits were turned in for DNA testing.
When the law takes effect in October, there could be thousands more rape kits submitted for DNA testing. If that happens, the state police labs may hire more scientists or hire out the work.
"It's going to depend on whether we outsource," said Vega. "We haven't outsourced since 2009. That may be an option...to out-of-state laboratories."
One option may also include advances in technology. The labs are already using robotics to assist in DNA analysis.
This week, state officials said they hoped to get federal money to doing more testing. The Human Rights Watch report found that 6,000 rape kits had not been tested. Their report only includes information from about half of the police departments around the state.