Rivera's first conviction was overturned by an appellate court because of trial errors.
The second conviction withstood review, but new evidence caused the judge to order a third trial. New DNA technology allowed Rivera's defense team to retest evidence and those tests excluded Rivera.
Jury selection got under way Monday at the Lake County Courthouse.
Jury selection will take at least another day. This trial is different from the other two by the simple fact that once the panel is finally selected, those jurors will hear that the DNA evidence in place does not link or tie Rivera to the crime scene.
A now 36-year-old Juan Rivera has spent 16 years in prison for the rape and murder of 11-year-old Holly Staker. First convicted in 1993, the man won a new trial in 1996 and was convicted again before again winning this latest trial after new DNA tests show samples from the crime scene don't match Rivera.
DNA is a pivotal part of the trial. Prosecutors could possibly explain the inconsistency by claiming the DNA sample was contaminated. The Lake County assistant state's attorney said they wouldn't be trying this case if they didn't believe he was guilty.
The 11-year-old was raped, stabbed 27 times and strangled on August 17, 1992, while she babysat at the home of a family friend.
Investigators eventually zeroed in on Rivera, who was then serving three years for burglary, after he was fingered by another inmate. After five days of questioning, police said Rivera confessed to the crime. His attorneys accused officers of coercing Rivera's confession as well as pressuring witnesses.
Rivera's defense attorneys say, under Illinois law, Rivera is presumed innocent. They also maintain that there is no conclusive evidence linking him to the crime.
This trial is expected to take two or three weeks and has a potential witness list that tops out at about 170. That includes friends and family of both the victim and the accused, as well as members of law enforcement and some individuals in the scientific community who are going to no doubt talk about the DNA evidence.