The 20th hijacker is a possible additional terrorist in the September 11 attacks of 2001 who, for unknown reasons, was unable to participate. The 20th hijacker, though not present during the actual attacks, is said to have been deeply involved in the preparations. There were many variations of the 9/11 plot, with the number of terrorists fluctuating with available resources and changing circumstances. In the end, there were 19 hijackers: three of the planes were taken over by five members each and the fourth was hijacked by four people. The latter plane, United Airlines Flight 93, crashed into a field near Shanksville, Pennsylvania, due to the resistance from passengers before it could reach its target in Washington, D.C. Hijackers Ramzi bin al-Shibh allegedly meant to take part in the attacks and may have been the intended hijacker-pilot of American Airlines Flight 77, but he was repeatedly denied a visa for entry into the US. His role as one of the four hijacker-pilots preceded Hani Hanjour. Mohammed al-Qahtani, a Saudi Arabian citizen, is often referred to as the 20th hijacker. José Meléndez-Pérez, a U.S. Immigration inspector at Orlando International Airport, refused his entry into the U.S. in August 2001. He was later captured in Afghanistan and imprisoned at the U.S. military prison known as Camp X-Ray at Guantanamo Bay, Cuba. In January 2009, Susan J. Crawford asserted that Qahtani's interrogation at Camp X-Ray amounted to torture. Zacarias Moussaoui, a French citizen of Moroccan origin, has widely been referred to as the 20th hijacker. Moussaoui may have been considered as a replacement for Ziad Jarrah, who at one point threatened to withdraw from the scheme because of tensions amongst the plotters. Plans to include Moussaoui were never finalized, as the al-Qaeda hierarchy had doubts about his reliability. Ultimately, Moussaoui did not play a role in the hijacking scheme. He was arrested about four weeks before the attacks. Moussaoui is now serving a life sentence for his involvement in the 9/11 attacks. He pleaded guilty in 2005 to collaborating with the other hijackers. Moussaoui claimed he and Richard Reid unsuccessfully attempted to hijack a plane on 9/11. According to the BBC, Fawaz al-Nashimi claimed to have been the "20th hijacker". An al-Qaeda video has been released from a US intelligence organization, showing al-Nashimi justifying attacks on the west. The U.S dismissed al-Nashimi's claims as propaganda. He was also known as Turki bin Fuheid