The film is an homage to the slasher film genre and features cameos from several veteran horror actors, including Robert Englund, Zelda Rubinstein, and Kane Hodder. The film premiered at the 2006 South by Southwest film festival and was shown at several other festivals. It received a limited release in the United States on March 16, 2007.
The film is shot as a documentary set in a world where the killers depicted in famous slasher films are real. A female journalist named Taylor Gentry and her two cameramen, Doug and Todd, document the preparations of Leslie Vernon as he prepares to join the ranks of other slasher villains. Leslie takes his identity from an urban legend about a boy who killed his family and was cast into a river by angry townsfolk.
He initially claims to be the vengeful spirit of the slain boy but soon admits that he is an ordinary man named Leslie Mancuso who must rely on conventional tactics rather than supernatural powers. Taylor and her crew film Leslie's meticulous preparations to slaughter a number of teenagers in an abandoned house and then be confronted by a virginal "survivor girl", Kelly. Taylor and her crew come to share Leslie's enthusiasm for his project, but their consciences catch up with them on the night of the murders.
They beg Leslie to call off his killing spree, but Leslie is adamant, believing that his survivor girl will define herself by facing him. Taylor and her crew abandon their documentary and at this point the film shifts from a documentary style to a traditional horror film presentation. Taylor attempts to warn and rally the remaining teens together to fight Leslie, but Leslie's preparations repeatedly give him the upper hand. The group looks to Kelly for leadership, but she unexpectedly dies.
Taylor quickly realizes that, as a virgin herself, she was Leslie's true survivor girl all along. Leslie continues picking off the group one-by-one until only Taylor remains. She faces Leslie and defeats him in the exact manner he had laid out for her, then burns down the shed in which he was defeated. She then runs into Doug and Doc Halloran who survived their encounters with Leslie. However, Leslie's preparations included learning to feign death and slathering himself with flame-retardant gel.
Over the final credits, security camera footage reveals Leslie's charred body sitting up on an autopsy table, still alive, accompanied by the song "Psycho Killer" by Talking Heads.
Behind the Mask was filmed largely in Portland, Oregon and the outlying towns of Troutdale, Banks, St. Helens, Estacada, and Sauvie Island. The establishing shots of Glen Echo were filmed on Main Street in downtown Troutdale. Filming took place in November 2004.
Due to the limited budget and location restrictions, some of the script was re-written during filming to accommodate the filming locations. During filming, several locations needed for certain scenes had yet to be scouted and were discovered in the middle of shooting.
Actor Scott Wilson became involved in the film after a suggestion from friend Robert Englund, who was already cast in the film.
Director Scott Glosserman recruited a group of young local filmmakers in Portland to work as additional editors on the film after seeing and being impressed by an independent film they had produced called The Black Shoe Drifter.
The film premiered at the South by Southwest film festival in March 2006, and toured at other festivals, eventually acquiring distribution from Anchor Bay Entertainment, who released the film limitedly in the United States in March 2007.
Behind the Mask was generally well received by film critics. Review aggregator website Rotten Tomatoes gives the film a 76% rating based on 37 reviews. The consensus states: "A smart mockumentary that presents a gory, funny, and obviously affectionate skewering of the slasher genre." On Metacritic, the film has a 66/100 rating based on 14 critics, indicating "generally positive reviews".
Elizabeth Weitzman of the New York Daily News called the film "a must for those who like thrills laced with a sense of humor" and noted the film's deadpan sense of humor. James Berardinelli said that it "provides a fresh, chilling breeze through the stale air of the crypt that has become multiplex horror", and awarded it three out of four stars, while the Los Angeles Times referred to it as "original and weirdly delicious, and executed with gory aplomb."
Stephen Hunter of The Washington Post said the film's "breakdown of cliches is vivid and witty", noting that its intended audience was "genre deconstructionists" and "smart young people who have studied horror/slasher movies and enjoy them for their vulgar energy." Hunter also called the performances of Baesal and Goethals "brilliant".
Contrarily, The Village Voice gave the film an unfavorable review, stating: "Desperately overcompensating for the fact that most horror films are already parodies of themselves, Behind the Mask takes a bite out of the dumb Scream franchise before devouring its own tail, proving that you are what you eat."
Tyler Doupe of Fearnet included Leslie Vernon in his list of "Ten of Horror's Most Disarming Psychopaths".
In an interview David J. Stieve, when asked if he was working on new scripts, said,
"Well, then you’re treading into sequel territory. If there is any kind of scoop, it’s not really a scoop but... I can tell you and your readers that there is a definite idea for what’s going to happen to Leslie Vernon next, that’s been the goal all along. There are a lot of what-ifs, and things to have to happen right in this business for that to ever come to fruition, but certainly if there’s going to be another horror movie coming from me, my biggest impulse, of course, is to relate what happens to Leslie next."
Baesel, when asked about the possibility of returning for a sequel to Behind the Mask, stated, "[...] there’s a certain chance. I know that ideas have already been circulating around Scott and David’s heads and I’d love to take Leslie on again. However, I don’t think we’d undertake a sequel unless the script is as good or better than Behind the Mask. The first was so good it would be pissing on Leslie’s legacy to set out with anything less than inspired ... and Leslie would never have that."