Legal counsels assigned to Gimpel were Major Charles E. Reagin and Major John E. Haigney. Colepaugh was represented by Major Thayer Chapman and Major Robert B. Buckley. During the trial, Colepaugh's defense claimed that the accused had a change of heart while in Germany, undertook the espionage mission as a way to get back to the US and turn himself in, but could not easily get away from a watchful Gimpel. The prosecution countered, saying that Colepaugh was often alone without Gimpel and had many opportunities to turn himself in during the month since he arrived in Maine by submarine, but failed to act on any of them.