In the six years since 28 people were charged in 22 cold case murders, Kane County prosecutors have secured 17 convictions.
Three more cases are pending and another man was sentenced to life in prison Tuesday for killing two brothers in 1993.
Authorities called Operation First Degree Burn, a joint investigation by the FBI, Aurora police and the Kane County State's Attorney's and Sheriff's offices a resounding success.
"We will not give up on behalf of victims," State's Attorney Joe McMahon said Tuesday during his monthly meeting with reporters. "Justice will come and I think it came rather loudly and clearly in those cases."
Aurora Police Chief Greg Thomas said there were an estimated 1,000 gang members in the city in the late 1990s/early 2000s. He now estimates there to be about 300. In 1996, 26 people were murdered in Aurora, and the city averaged 14 homicides each year until 2007, when it again hit 26 murders.
Since First Degree Burn, in which cases were bolstered by former gang members testifying against other gang members, Aurora has averaged about 2.5 homicides a year, Thomas pointed out.
Last year was the first homicide-free year in Aurora since 1946.
"First Degree Burn was a big part of making that happen," Thomas said, adding that the crime rate has dropped 40 percent in the last five years and community groups are working more with police. "The image has changed a little bit for Aurora. The perception has changed. There is still work to do. Perception has followed reality a little bit."
McMahon and Thomas don't believe they can fully eradicate gangs. Lawsuits filed against gangs and gang members to prevent them from congregating and recruiting new members are the next step to further reduce crime and gang activity.
State's attorney's offices normally have conviction rates of around 95 percent when looking at all cases charged -- ranging from traffic offenses and misdemeanors to felonies.
Kane County prosecutors secured convictions in roughly two of every three cold cases, although in some cases the charges were dismissed because the defendant was already serving a life prison sentence.
Six defendants were found not guilty of all charges; McMahon said the cases were tough cases to try.
Many relied on former gang members testifying against each other; but testimony was corroborated by other witnesses and in some cases DNA evidence.
"Everybody should be incredibly satisfied with the conviction rate," said Kane County First Assistant State's Attorney Jody Gleason. "The fact that it's 20 years old certainly doesn't make a difference to us if we can prove the case. It was a huge message to the community (filing charges in First Degree Burn)."
Gleason pointed to the life sentence issued Tuesday to Michael Reyes for the 1993 murders of teen brothers Jesus and Francisco Montoya of Montgomery.
One of their sisters, Valentina Montoya Cisneros, testified at the sentencing that bringing Reyes to justice has helped her family heal.
"After today, I will forget the day that Frank (Francisco) and Jesus were taken from our family. Instead, I will remember that my family can now be at peace and that my brothers are with me always," she said.