Noir fiction. (Genre/Form Term)

Oxford dictionary of literary terms, via Oxford reference online, Nov. 2, 2012 (noir: a kind of crime novel or thriller characterized less by rational investigation (as in the classic detective story) than by violence, treachery, and moral confusion; although noir fiction derives in important ways from the hard-boiled school of detective writing and overlaps with it at some points ... it can be distinguished from most detective stories and from other kinds of thriller by its powerful tendency to dissolve orderly distinctions between the roles of criminal and hero; hard-boiled: a term applied both to a certain kind of detective character, usually a world-weary private investigator, and to a special tradition of American detective story in which these characters are prominent)

GSAFD, 2000 (Noir fiction. A category of modern crime fiction; use for fiction of crime and detection, often in a grim urban setting, featuring petty, amoral criminals and other down-and-out characters, and permeated by a feeling of disillusionment, pessimism and despair. BT Mystery fiction)

Donnellan, M. El Nino : a crime-noir thriller set between Galway and Mayo, 2012.

Fiction that features violence and treachery and a lack of distinction between criminals and heroes.