Sean was a professional screenwriter from 1998-2018. He is known for both horror films and swords-and-sandals movies.

After graduating from Brown University with a double major in pure mathematics and studio art, Sean spent several years working in Hollywood as a set dresser, prop assistant and art director working with filmmakers as diverse as James Cameron, David Fincher, and David Lynch.

He began writing and directing his own films in 1992 as a founding member of Filmmaker's Alliance. He continued his studies at USC's School of Cinematic Arts, graduating in 1997 with an MFA in production. His student film, The Shy and the Naked, won a grant from the Sloan Foundation. His short film Melancholy Baby won the Los Angeles Short Filmmaking Grant, presented to him by Eastman Kodak at the Directors Guild of America.

After finishing film school, Sean got his "big break" when his first major spec script was purchased by MTV/Paramount in 2000, which led to a deal with Dimension Films. Over the next two decades, while working on genre features such as Halloween: Resurrection and Conan The Barbarian, Sean returned to USC to teach screenwriting at the John Wells Division of Writing for Screen and Television. He also wrote the popular screenwriting blog, Genre Hacks.

His last screenwriting projects included MER, a horror movie about lascivious, man-eating mermaids, written for producer J. Todd Harris and director Mary Lambert.