Jeffrey Sebelia is an American fashion designer, musician and founder of the clothing label Cosa Nostra, which he headed from a loft on Broadway in downtown Los Angeles.

After a successful drug rehabilitation at the age of 31, Sebelia enrolled in sewing classes at Los Angeles Trade-Technical College.

Among the label's celebrity clients were Dave Navarro, Gwen Stefani, Jennifer Lopez, Red Hot Chili Peppers, Marilyn Manson, Elton John, Madonna, and Tommy Lee.

In the spring of 2006, Sebelia auditioned for the Bravo series Project Runway after seeing the success his friend, former contestant Santino Rice, had enjoyed.

He had been portrayed as the third season's "villain," notorious for his explicit language and making fellow contestant Angela Keslar's mother cry when he worked with her as a client for a challenge.

His winnings included $100,000 to develop his own clothing line, a 2007 Saturn Sky Roadster, a year's representation by Designer's Management Agency, and a 15-page spread - featuring Marilinda Rivera, the model with whom he was paired during most of the Project Runway challenges - in ELLE magazine.

[3] Chester Bennington of Linkin Park, who was also an avid client, loved the Cosa Nostra line and knew Sebelia for years.