I remember this series very well.
Goofy teethed Ron Liebman starred as a convict who while in prison, for what I don't remember, studies law. When he is released he becomes a fully fledged legal-eagle, and sets about championing the causes of the down at heel. All very very believable stuff indeed. It was almost like a naughty version of Petrocelli, but without the unfinished house. It is especially memorable to me because of it's intro sequence, which featured animated still photos, which seemed to be the in thing with title sequences back in the '70s; ie, Baretta, Police Woman etc.
