I've never seen "Trials of O'Brien". If it's anything like "Late Night With Conan O'Brien," then it's probably pretty funny. I wonder if the two characters are supposed to be related?
Daniel J. O'Brian was an unorthodox criminal defense attorney, who despite the luxury office with faithful secretary, was a gambler, pool player, bet on the horses, etc. He was either rolling in dough, or dead broke. Consequently, he was always behind in his alimony payments and paying secretary's salary, etc. Guest defendant each week in which O'Brien got off, of course. An investigator named McGonogol (dressed like a vaudeville comedian) was hysterical--carried around a large briefcase and the routine was that he had to go through it every time to find things. It was a great show, wonderful cast, and the only good thing about its cancellation is that Falk went on to do Columbo.