Working under pseudonyms such as Helmuth Richler, Warren Evans, Russ Carlson, Oscar Tripe, and Amanda Barton, Costello directed such well known adult features as Forced Entry, Midnight Desires, Water Power and Dracula Exotica. Costello was the first director to methodize the construction of a pornographic movie, and created a formula that allowed him to mass produce them in quantities that, until then, would have been unthinkable. His formula would be copied for years to come, and would forever change the way sex films were made.
According to his own account, Costello got his start as a porn actor in the late 1960s, appearing in silent 16mm and 8mm loops created for the burgeoning peep show market in New York's Times Square. Eventually he began directing his own porn loops featuring, in addition to himself, such early porn luminaries as Harry Reems, Fred Lincoln, Laura Cannon, Tina Russell, and Jamie Gillis.
In 1971, Costello directed his first feature film, Forced Entry," an eerily violent hardcore sex and gore feature about a Vietnam vet who stalks, rapes and murders various women. Budgeted at only $6,200, the film starred Harry Reems (under the pseudonym Tim Long) as the serial rapist, and Playboy Magazine's Playmate Laura Cannon as a surprisingly convincing victim. Costello put stock black and white news footage of the Vietnam war to good use, intercutting it with his hero's murder spree, and scored these scenes with moody and effective Vietnamese music. Forced Entry'' would appear to have been theatrically released by Sherpix in 1972, but seems not to have galvanized conspicuous commercial interest. With the advent of the Grindhouse phenomenon, "Forced Entry" was re-released on DVD by After Hours Cinema, and has gained almost legendary status, and a worldwide fan base. Oddly enough, "Forced Entry" was the first feature film to include the Vietnam War as thematic to its story line.
In 1973, Costello became the most prolific producer/director of low budget porn features in the emerging New York adult film scene. Known as "one day wonders", Costello's films of this period were hour-long, 16mm sound features produced for $5,000 a piece and shot in a single day (ergo the name "one day wonder"). Although based on roughly planned story lines, most of the dialogue in the films was improvised by the actors, among whom were typically such personalities as Levi Richards, Ashley Moore, Georgina Spelvin, Marc Stevens, Tina Russell, Jamie Gillis and Costello himself. Costello asserts that the backers of these productions were associates of the Gambino crime family, a Mafia organization based in New York. His earliest such features were Joe Rock Superstar and Honeymoon Suite.
By 1974, Costello was able to secure bigger budgets for his productions and began to write complete screenplays. The first of his scripted features was The Passions of Carol, based on the Charles Dickens story A Christmas Carol. The film's backers, thinking that the costumed, and sometimes hilarious little epic, might have appeal beyond the porn market, attempted a crossover release. This would be the first motion picture containing hard core sex scenes to open in a straight theater. It opened in the Spring of 1975 at New York's Quad Cinemas to mixed reviews, and did very little box office. Costello, who claimed that his Christmas fantasy was among his favorite efforts, also considered it his first box office "turkey". In an internet interview, Costello claimed, "I loved making this picture. It was big. It was loud, It was colorful. It was funny. I just forgot to make it sexy".
In 1976, Costello directed one of his most notorious features, Waterpower (aka The Enema Bandit). Costello asserts that the film was directly commissioned by Robert "Dibi" DiBernardo, a capo in the Gambino crime family who ran that organization's sizeable porn interests. Based on a true story about a man convicted on assault charges, stemming from the forceable administration of enemas to college co-eds on the Urbana campus of the University of Illinois, the film features actor Jamie Gillis as a disaffected enema fetishist, who dedicates himself to cleansing women of their "vile humors", in order to save them from their sins. It is claimed that the film failed commercially in its initial release, prompting its producers to re-release the film with the claim that it was directed by adult film icon Gerard Damiano. The rights to the film were eventually sold to porn mogul Rueben Sturman, who distributed it in Europe and Japan, where it reportedly enjoyed enormous success. Costello claims that DiBernardo, and his associates in the "Gambino" crime family, were embarrassed by the film's subject matter, and refused to look at any of the footage. Realizing that the backers would not see the film before it opened, Costello asserts that he decided to turn the story into a parody of Scorscese's "Taxi Driver", with Jamie Gillis playing the Deniro role. Costello looked at the movie as an absurd comedy, and considered it to be the funniest movie he ever made. Over the years it has become a cult classic, apparently counting among its fans director Quentin Tarantino.
By 1980, Costello was making big budget porn films such as "Pandora's Mirror", "Hot Dreams", "Beauty" and "Dracula Exotica" for Reuben Sturman's organization. These were considered to be some of the very best examples of what has been called the "Golden Age" of porn. Burned out after a more than a decade of the "sex and drugs" lifestyle, Costello left the adult film industry in 1983. He moved his talents over to Madison Avenue, where he enjoyed a lengthy, award winning career directing television commercials for New York based advertising agencies. In between advertising endeavors, Costello briefly returned to the feature market, and directed the Horror Feature "Popcorn" in 1991 under the moniker Warren Evans. He is presently working on a memoir.