Within months of Friday the 13th‘s conquering of the box office filmmakers were exploiting every possible holiday and anniversary in the hope of capitalising on its success. By the end of the year audiences had also been subjected to Prom Night, New Year’s Evil, Mother’s Day and Christmas Evil (also known as You Better Watch Out), so it was inevitable that sooner or later weddings would be the next target. Perhaps the most important day of a young girl’s life, this seemed like the perfect companion to the slasher flick, which itself was something to be dreaded and feared. Released during the height of the slasher boom, Armand Mastroianni’s He Knows You’re Alone would earn a modest amount on a budget of just $300,000, although critical opinion would be decidedly mixed. But over the years it has come to be considered amongst the best of the early eighties slashers, later providing an inspiration for Scream 2 and helping to launch the acting career of a young Tom Hanks.
Having spent his youth creating 8mm shorts with his friends whilst studying at the College of Staten Island, Armand Mastroianni had always wanted to forge a career as a professional filmmaker. During pre-production of a comedy that he intended to shoot in Brooklyn, Mastroianni was introduced by his friend, George Manasse, to producers Joseph Beruh and Edgar Lansbury, who were expressing interest in funding a low budget horror. Mastroianni had recently signed with the William Morris Agency and so was taken seriously as an artist, and a meeting was arranged where he was asked to pitch an idea for a movie. Unprepared, he began to improvise and told an old urban legend about a young couple making out in the woods who are attacked by a deranged killer. The two men seemed unimpressed and so Mastroianni was forced to add a new twist and so suggested that this sequence was in fact part of a movie which a group of kids were watching at a cinema, where a real maniac was out to kill. Impressed, they immediately commissioned Mastroianni and his writing friend, Scott Parker, to adapt the concept into a workable screenplay, which was to be titled Blood Wedding.
Attending a screening of the urban legend horror, young bride-to-be Marie (Robin Tilghman) is too scared by the events on screen so she decides to escape to the restroom downstairs. Whilst in the cubicle, she becomes convinced that someone is lurking around outside and so nervously returns to her friend, who is still enjoying the movie. After trying to convince her to leave after claiming that someone is following her, Marie settles down and tries to ignore the film, but a figure sits down behind her. He slowly pulls a knife out of the inside of his coat and, as the young woman in the movie is stabbed, he forces the blade through the back of her chair and straight into her heart. Washed out cop Detective Gamble (Lewis Arlt) arrives on the scene and is notified by one of his colleagues, Frank Daley (Paul Gleason), that the victim was due to marry. This intrigues Gamble as he had previously been obsessing over catching a maniac who had been targeting similar victims and had succeeded in evading capture.
In a flashback we see that Gamble was due to marry a beautiful young woman but just before their wedding she was brutally murdered by her ex lover, Ray Carlton (Tom Rolfing). Meanwhile, Amy Jensen (Caitlin O’Heaney) is another future bride whose fiancé, Phil (James Carroll), is leaving for a bachelor weekend, leaving her alone with her friends Joyce (Patsy Pease) and Nancy (Elizabeth Kemp) to search for a wedding dress and have a sleepover while her parents are also absent. All the while an ominous figure follows her around, much like Michael Myers in the first Halloween. Another presence is Marvin (Don Scardino), her own ex boyfriend who she still seems close to, something which arouses jealousy in her partner. But is isn’t long before Amy attracts the attention of Carlton but can Gamble finally get revenge before it is too late?
He Knows You’re Alone certainly is not one of the better slashers. Despite the opening gimmick of the film-with-a-film (something which Lamberto Bava succeeded more impressively with in his 1983 giallo La casa con la scala nel buio, aka A Blade in the Dark), the effects during this sequence, most notably the amateur blue screen which reveals that the cinema screen was superimposed during post-production, are below the standard of even the most mediocre of slashers. The fact that the killer’s identity is revealed almost immediately also takes away from the suspense, much like When a Stranger Calls would do after its impressive opening act. Rolfing does deliver an impressive performance as the deranged killer, close ups of his piercing eyes adding an interesting element to the murder set pieces. O’Heaney is by no means the worst final girl but she is nothing special, lacking any kind of immediate appeal or individuality. Arlt’s turn as the burnt out detective may seem like something straight out of a TV movie but that is part of its charm, and the presence of Gleason (who would later make a name for himself for his nasty roles in the likes of Trading Places and The Breakfast Club) is always a welcome addition.
Whilst some slashers succeed in being more suggestive than graphic – Black Christmas and Halloween are perfect examples – occasionally gore is a welcome addition when script and characterisation fail to impress. To Parker and Mastroianni’s credit, they do flesh out their protagonist as much as possible but the majority of the film’s running time is so uneventful that too much of the film’s impact relies of how interesting you find the characters. Hanks’ appearance an hour into the movie does little to add to the proceedings as he was so sadly underused, and the director’s decision to change the script so he survived until the end takes away from the fun of watching an A-list celebrity being butchered. The film’s most effective moment is when Amy finds the severed head of one of her friends in her fish tank, although O’Heaney’s subsequent reaction seems less than convincing. Whilst He Knows You’re Alone was an admirable effort from Mastroianni, it falls short of so many other films that were released around that time (such as Terror Train, My Bloody Valentine, The Prowler and Happy Birthday to Me to name a few) and offers very little in the way of thrills.