Order & law is an American police and play television series. It originally aired on many different cable networks and , in syndication, on NBC. Order & law expired on September 13, 1990, also completed its final and 20th season on May 2-4, 2010. Law and Order was the longest-running crime play on prime time television. After The Simpsons Gunsmoke & Order and Law tied for the second longest-running scripted American prime time show with characters that were ongoing.