Two of the defendants were each charged with four felony counts related to conspiracy to distribute obscene materials, transportation of obscene matter, aiding and abetting, and mailing obscene matter.
Santilena was charged with one count of conspiracy to distribute obscene materials and one count of mailing obscene matter, the U.S. Attorney stated.
The indictments stem from a series of websites the defendants were running, starting in 1998, that prosecutors say featured streaming video of rape scenes and sexual torture.
Santilena joined the operation in 2002.
The defendants allegedly used two distribution channels for the content: one via the Internet in pay-per-view format, and the other in the form of commercially distributed DVD and VHS tapes through the U.S. Postal Service.
The FBI and U.S. Postal Inspection Service got a lead in the case following a similar obscenity indictment against Garry Layne Ragsdale and his wife, Tamara Michelle Ragsdale, who at one time were distribution partners with Gartman.
The Ragsdales were convicted on obscenity charges in October of 2003 and later sentenced to several years in prison.
Gartman and McDowell, both U.S. citizens, are currently being extradited from Canada back to Texas. Defendant Santilena is a resident of Henderson, Nevada, and will be required to face charges in Dallas, the U.S. Attorney's office stated.
According to Boyle, the indictment was returned late Thursday by a federal grand jury in Dallas. If convicted on all counts, Gartman and McDowell could each be sentenced to 20 years in prison with a $750,000 fine.
Santilena faces a 10-year sentence if convicted on all counts and a $500,000 fine.