Mystery of the Week

A format where the main characters solve a mystery each weekly episode.

Almost every Detective Drama sticks primarily to this format, though some recent shows (eg. the CSI franchise) has upped the ante to two murders per week, one in the A plot and the other in the B plot. Notable exceptions are Murder One, which devoted an entire season to each case and the early seasons of Homicide: Life On the Street, in which detectives would typically work three or four cases at the same time, each case taking several episodes to close (In fact, sometimes they wouldn't solve the case at all, and a case opened in the first episode remained open in the finale). In later seasons, they yielded to network pressure and became a standard Mystery of the Week show.

Notable Examples:

 * Columbo
 * Diagnosis: Murder
 * House also arguably qualifies.
 * Law and Order and its spin-offs.
 * Monk
 * MacMillan and Wife
 * McCloud
 * Midsomer Murders
 * Mrs. Columbo (later called Kate Loves A Mystery)
 * Murder, She Wrote
 * Vampire Prosecutor
 * Veronica Mars