ABC7'S Jason Knowles found records that show judges have been letting some offenders off easy.
No matter which side of the gun control debate you're on, there are current laws that can severely punish criminals using illegal, unregistered guns.
But many of those people are quickly back on the streets, and some go on to be alleged murderers.
Seventy-four-year-old William Thomas, a South Shore neighborhood janitor, was an innocent victim of gang gunfire.
"And it still hurts because when we come out here you can see where he would be," said Muriel Blue, victim's best friend.
One of the alleged killers, Aramis McKinzie, could have been behind bars at the time of the October 2012 murder. In 2011, he was convicted of illegally using a weapon, but ended up back on the streets within months. And 24-year-old Darryl Chambers, seen during an ABC7 I-Team report on gangs, got two years probation for unlawful use of a weapon in 2011.
Police say he, too, could have been in prison but instead, he's now charged in a shooting that injured three people on the Fourth of July. One of them was five-year-old Jaden Donald.
There are already several laws on the books which allow judges to give people wielding illegal guns several years behind bars, but that may not be happening. Law enforcement officials say many times they see criminals only getting one year minimum or even probation.
There were 2,000 offenders in 2012 convicted of "aggravated unlawful use of a weapon," for holding an illegal, unregistered gun without a FOID card. That charge carries a minimum of 1 year and a maximum of 3 years.
The Circuit Court of Cook County wouldn't tell ABC7 how many offenders received the minimum, but did provide us with raw data. Out of 36,000 individual charges in 2012, ABC7 found that only 12 percent resulted in a sentence- the majority of those sentences were a year or less.
"The offender is always subjected to automatic good time and credit for the amount of time they spent in custody prior to trial. . . So today if someone is sentenced to the minimum of 1 year we are talking 6 months or less and usually less and we have seen one case where an offender spent 61 days in custody," said Cook County State's Attorney Anita Alvarez.
Chicago Police also point to almost 100 gun offenders this year back on the street within months and then charged again with shooting or killing.
"We are taking those guns off the street and locking people up but now at the end of the day what happens when we make that arrest and many times we find out individuals get probation or no jail time, boot camp," said Chicago Police Superintendent Garry McCarthy.
"Why aren't we giving the maximum sentences for people carrying illegal guns and for people involved in shooting we have got to turn this around the city is under siege," said Jody Weis, ABC7 public safety expert.
Now law enforcement officials are pushing legislation in Springfield which would strengthen current laws by increasing minimum sentences and enforcing truth in sentencing.
Police Superintendent Garry Mccarthy says similar laws are working in New York, because gun offenders are afraid of facing serious prison time, so they don't commit the crime.
ABC7 requested an interview with the chief judge about this story. He declined to be on camera, but in a statement said: "The duties of the judiciary are to administer fair and impartial justice. Chief Judge Timothy Evans has every confidence that the judges of the Circuit Court of Cook County will continue to perform their duties."
Prosecutors and law enforcement officials say they don't believe any specific judges are to blame for offenders getting off easy.