Well he had already played the baddie as Blofeld in James Bond (1960's). But his very best performances were always in Kojak, he was very gritty and I'm sure he went off script on loads of occassions to lend extra credibility to the role. To be honest I'm not sure that he would have made a good murder suspect in Columbo. Or perhaps yes... the only one that ever got away with it! (Not including Forgotten Lady of course!).