Many reviewers commented upon Shutter Island's release that the film ultimately succeeds because Martin Scorsese's singular directorial ability elevates a story that often threatens to veer into B-movie camp territory. Critics likely expected another gritty crime drama following the runaway critical and commercial success of Scorsese's The Departed (2006). However, with Shutter Island, set somewhere in the Boston Harbor Islands in 1952, Scorsese intentionally sets out to pay homage to pulpy and sensationalistic postwar genres like the film noir, the monster movie, and the police procedural.
Shutter Island is moreover a film that revolves around notions of performance, illusion, and theatricality, and in many ways functions as a testament to the power of the moving image. The structure of the plot, in which Cawley's efforts to "direct" the action of the plot are concealed from the viewer, reflects the way film directors like Scorsese create complex illusions for their audiences. In this light, one of the film's central images—the lighthouse—might be interpreted as something like a seeing eye or roving camera lens.
The work in Scorsese's filmography with which Shutter Island can most easily be compared is Cape Fear (1991), Scorsese's remake of J. Lee Thompson's 1962 neo-noir thriller. Shutter Island reflects many conventions of the film noir genre, featuring a morally compromised protagonist (Teddy Daniels), a femme fatale (Dolores Chanal), and a plot replete with double-crossing and conspiracy. Like Cape Fear, which stars Robert DeNiro as a violent ex-con, Shutter Island also features a tormented man whose capacity for violence becomes the focus of the film. For their roles, Scorsese instructed Leonardo DiCaprio and Mark Ruffalo to study Dana Andrews's performance in Otto Preminger's 1944 film noir Laura.
Scorsese was also heavily influenced by low-budget horror features produced by RKO Studios under Val Lewton, such as Cat People (1942), The Seventh Victim (1943), and Isle of the Dead (1945). Like these films, Shutter Island is, in its own way, a monster movie—the femme fatale Dolores Chanal is undoubtedly monstrous for the triple homicide she commits, and the protagonist Teddy Daniels is himself accused of being a monster by Dr. Naehring. Scorsese's flashbacks to Nazi Germany lend a grandiose sense of historical monstrosity to the already traumatic circumstances of Teddy's checkered past.
Scorsese's attempt to elevate B-movie schlock into the realm of pure cinema also led critics to compare Shutter Island to the mature work of Alfred Hitchcock, who sought to achieve something similar with twisty thrillers like Vertigo (1958) and Psycho (1962). Scorsese even counted Robert Wiene's 1920 German expressionist silent film The Cabinet Dr. Caligari as one of his chief influences when bringing Shutter Island to life on screen. What results is a vivid patchwork of genres tied together by the twists and turns of Laeta Kalogridis's adaptation of Denis Lehane's 2003 novel.
