Crime comics is a genre of American comic books and format of crime fiction. The genre was originally popular in the late 1940s and early 1950s and is marked by a moralistic editorial tone and graphic depictions of violence and criminal activity. Crime comics began in 1942 with the publication of Crime Does Not Pay published by Lev Gleason Publications and edited by Charles Biro. As sales for superhero comic books declined in the years after World War II, other publishers began to emulate the popular format, content and subject matter of Crime Does Not Pay, leading to a deluge of crime-themed comics. Crime and horror comics, especially those published by EC Comics, came under official scrutiny in the late 1940s and early 1950s, leading to legislation in Canada and Great Britain, the creation in the United States of the Comics Magazine Association of America and the imposition of the Comics Code Authority in 1954. This code placed limits on the degree and kind of criminal activity that could be depicted in American comic books, effectively sounding the death knell for crime comics and their adult themes.