Sergeant George Kramer is an L.A.P.D. homicide detective who has worked with Lieutenant Columbo on a number of occasions. Played by Bruce Kirby, Sergeant Kramer is the most frequently recurring character on Columbo, having appeared in six episodes; By Dawn's Early Light, A Deadly State of Mind, Identity Crisis, Last Salute to the Commodore, Columbo Cries Wolf and Agenda for Murder. Four of these episodes were starred in and/or directed by Patrick McGoohan who evidently liked working with Kirby.
Kirby additionally played a lab attendant named Doug in Lovely But Lethal, a TV repairman in Make Me a Perfect Murder and, somewhat bizarrely, a completely different police sergeant named Phil Brindle in Strange Bedfellows.