The other – very compelling evidence from an FBI forensic scientist from Virginia.
He testified the FBI is no longer doing the type of bullet analysis that played a role in convicting Dickens. That's because new government-funded research shows it might not be accurate.
During Dickens' original trial, the state compared the bullets found in Corporal DeGuch to a box of bullets in Dickens' bedroom.
They used FBI lab analysis to support that evidence.
Prosecuting attorney Joel Gabrielse spent several minutes asking that "expert" how much he gets paid to testify in court cases and asked how much of his own research he uses, as opposed to research conducted by other people.
Remember, that trial was in 1999.
But in 2005, the FBI quit using that kind of bullet analysis because new research shows they couldn't be 100% sure bullets like that came from the same box.
Dickens' case is one of up to 6,000 in the country affected by that research.
He was 16 in 1997 when DeGuch died, and throughout his trial, he denied shooting the officer but never denied being there when it happened.
Dickens appealed his conviction in 2001, but the Indiana Supreme Court denied that appeal.
Now, he's hoping the judge listening to his case will decide there's enough new evidence to move forward with a second trial.
This hearing is expected to wrap up on Wednesday, and the judge will likely think about it for a couple of days or weeks before making her decision.
Corporal DeGuch left behind a wife and three very small children. They were all in the courtroom on Tuesday. His daughter was just 2-months-old when he died.
Families of other fallen South Bend officers were also there, including loved ones of Scott Severns, who was shot and killed in 2006 and Tom DeRue, who was shot and killed in the 1970s.
It's part of the support system these families have for each other.
The judge has 90 days to make her decision, and she told WSBT she will likely use all of it.