A Connecticut judge has declared a mistrial in the case involving an 11-year-old girl who was raped and killed over a revelation involving decades-old evidence. Marc Karun, 60, was on trial on murder and kidnapping charges stemming from the alleged killing of Kathleen Flynn, according to FOX 61. Flynn, a sixth grader, was reportedly walking home from Ponus Ridge Middle School in Norwalk when she was attacked on Sept. 23, 1986. Her body was found in the woods along a path to nearby Hunters Lane.  REALTOR'S COLD CASE MURDER FINALLY SOLVED AFTER 15 YEARS, POLICE SAYWhile the case ran cold for a period of time, Karun was taken into custody at his home in Stetson, Maine in 2019.During Karun’s trial in Stamford last week, prosecutors revealed that they received an email from retired Norwalk police lieutenant Robert Fabrizzio disclosing that shortly after Flynn’s body was discovered, a state crime lab officer informed him that she had been disposed of in a used body bag, FOX 61 reported. Fabrizzio reportedly informed prosecutors that he was concerned about the possibility of evidence contamination in the case, leading Judge John Blawie to declare a mistrial – though he did not dismiss the charges against Karun.DAUGHTERS’ RELENTLESS SEARCH SHATTERS ‘OVERDOSE’ CLAIM, LEADS TO ARREST IN MOM’S 1992 MURDERThe state crime lab officer who made the revelation about the body bag was 87-year-old Henry Lee, a famous forensic scientist who previously worked on the O.J. Simpson murder trial and worked as the head of the lab at the time, according to FOX 61. Lee died last month."We’re obviously disappointed by this turn of events, especially for the family members of Kathy Flynn, who have waited 40 years for justice and some degree of closure," State Attorney Paul Ferencek said in a statement, FOX 61 reported.  YALE PROFESSOR’S FATHER CHARGED IN MOTHER’S DECADES-OLD MURDER, SAYS HE ‘USED ME AS BAIT’: REPORTProsecutors are now working with the medical examiner’s office and state crime lab to verify if the revelation is true.FOLLOW THE FOX TRUE CRIME TEAM ON XThe information surrounding the body bag was reportedly a surprise to crime lab officials, agency spokesperson Rick Green said."This is all a surprise to us. We stand by our testimony in the case," Green said in a statement to Fox News Digital, adding the agency has no further comment.SIGN UP TO GET TRUE CRIME NEWSLETTERKarun previously served 10 years behind bars after being convicted of sexually assaulting or kidnapping four other female victims throughout the 1980s, FOX 61 reported.SEND US A TIP HEREDNA testing technology advancements and the case’s similarities to Karun’s other attacks reportedly lead investigators to take him into custody in 2019. LISTEN TO THE NEW 'CRIME & JUSTICE WITH DONNA ROTUNNO' PODCASTShortly after Karun’s arrest, police found nearly 90 guns inside his Maine home, which he was barred from owning as a convicted felon, according to FOX 61.LIKE WHAT YOU'RE READING? FIND MORE ON THE TRUE CRIME HUBIn 2024, he pleaded guilty to federal gun charges stemming from the allegations and is set to be sentenced this summer. Karun remains in custody on a $5 million bond. The State’s Attorney’s Office and Karun's defense counsel did not immediately respond to Fox News Digital's request for comment.