LONDON -- The Ohio Innocence Project has received over 6,000 letters and calls from inmates proclaiming their freedom.

Of those, this non-profit team of attorneys and law students based at the University ofCincinnati has taken just 24 cases to court for post-conviction DNA testing.

And of those 24 cases, 15 convictions have been overturnedby by the DNA testing. Many of the rest of the cases are still pending.

The Innocence Project started 20 years agoand came to Ohio in 2003.

Staff Attorney Carrie Wood says Doug Prade's case, which they took up in 2004, is one of the longest ongoing cases for the OIP.

"Why the state spent eight years litigating it, spending tax payer money when DNA testing was going to be provided pro bono, there is no good answer to that question," Wood said.

She says the attorneys with the Ohio Innocence Project will have to continue working with Prade, now that prosecutors have appealed his release.

If the court upholds his innocence, Prade could be entitled to hundreds of thousands of dollars in compensation for his 15 years spent in prison.

"There should never be an innocent person in prison and our criminal justice system unfortunately has flaws," Wood said.

She says it is the objective of the Ohio Innocence Project to expose those flaws, for the sake of the person behind bars, and for the betterment of the justice system.