In a lot of TV shows, the abbreviation M.O. is used to ask how the crime was committed. M.O. is actually an abbreviation from a Latin phrase. The phrase is Modus Operandi. Its translated as method or mode of operation. Method of operation is another way of saying/asking how the culprit committed the crime. Now, when you watch Criminal Minds, Law and Order, or any crime TV show, be sure to pay attention to the Modus Operandi!