Ronald McIntosh (D1) disappeared on October 28, 1986, during an unescorted transfer from F.C.I. Pleasanton to the federal prison at Lompoc. D landed a helicopter in the Pleasanton recreation yard on November 5, 1986, and flew off with Samantha Lopez (D). They were apprehended ten days later in a Sacramento shopping mall where they were buying a set of wedding rings. D was charged with escape from federal custody. D1 was indicted for air piracy, use of a weapon to commit a crime, and aiding and abetting D's escape. Ds contend that they are both entitled to raise the defense of necessity/duress to their charges. Before the judge was a motion in limine by the United States (P) to bar the presentation of on the defense of necessity/duress.