HERRIN, IL - A local mother is making it her mission to fix what she says is a broken justice system.  Peter Kerrigan of Herrin, Illinois was convicted of shaking 22-month-old Brynden Gibson to death three years ago.  Kerrigan was sentenced to ten years in prison Friday.  With good behavior he could be out in less than three.
        
Kerrigan was originally charged with first degree murder and aggravated battery, but in a plea agreement his sentence was reduced to involuntary manslaughter.
 
His sentence was reduced because of a technicality. The expert witnesses who conducted Brynden's autopsy would not testify in court.  States attorney's were forced to drop first degree murder charges to involuntary manslaughter.  The victims mother is upset.  "I felt devastated.  I felt lost. I felt failed by the system you know more importantly they let my son down.  A system that said we won't let you down," but Rebecca Gibson feels not only let down but betrayed by that system.

Her son was rushed to a St. Louis hospital where he died December 12, 2006.  St. Louis County Chief Medical Examiner Dr. Mary Case examined the boys damaged brain.  Williamson County States Attorney, Chuck Garnati asked Dr. Case to testify in court because he needed her expert testimony to pursue a first degree murder charge.
           
"I told him I would appear if I was subpoenaed, but I did not because I do many of these examinations.  I don't like to have to go to court for every time that I examine one of these brains," said Case.
 
Garnati's office sent multiple subpoenas, but claims Dr. Case and others dodged them.  His assistant Lisa Irvin said, "We did not back down on this.  This was the best resolution we can have."

Rebecca Gibson believes the breakdown between the St. Louis medical examiners and Garnati let her sons killer get away with murder.  "I'm at a point to where I want to fight and I'm going to fight.  I'm going to fight for my son.  I'm going to fight for the other babies.  It's not just about us anymore.  It's about everybody," said Rebecca Gibson.

She expects to talk with Representative John Bradley next week to work toward improving communication between medical examiners and lawyers.  Rebecca Gibson hopes to make a change so that her son will not have died in vain.
 
Illinois has some of the strongest laws in the nation against adults who shake babies.  Offenders can be charged with first degree murder and aggravated battery.