A couple of clips regarding the Alien autopsy. So first of all we have Stanton Friedman on exactly Why The Alien Autopsy video is fake, then we have the Alien autopsy footage itself.
The term alien autopsy is used within the UFOlogical community to refer to the supposed examination of an extraterrestrial cadaver by government authorities. Belief in alien autopsies is a common element of UFO conspiracy theory. Film footage, purporting to show an alien autopsy was promoted during the 1990s by Ray Santilli, a London-based video entrepreneur. However, Santilli announced in 2006 that the film was not genuine.
Ray Santilli and fellow producer Gary Shoefield announced that their film was only partially real (a "few frames", in their words), while the rest was a reconstruction of twenty-two rolls of film, averaging four minutes in length, which Santilli had viewed in 1992 but which had subsequently degraded from humidity and heat. They said that only a few frames of the original were still intact by the time they had raised enough money to purchase it. Santilli and Shoefield stated that they had "restored" the damaged footage by filming a simulated autopsy on a fabricated alien, based upon what Santilli saw in 1992, and then adding in a few frames of the original film that had not degraded. They have not identified which parts are original footage.