Mitch is a man in jail in Coral Palms, Flordia who has a glass eye.
Throughout the Series
In the Season Four episode, Coral Palms Pt. 2, Mitch met Jake Peralta and Raymond Holt in the Coral Palms, Florida jail.
He offered to assist in Holt and Peralta's jailbreak with his offering being that he had a glass eye.
It was thanks to this glass eye that Jake was able to get rid of one of the two deputies so they could successfully escape.
Mitch removing his glass eye and giving it to Peralta to throw