Three defendants, Robert Jackson, William Scott, and Martin Allen, appealed their convictions for conspiracy to commit armed robbery, attempted robbery, and possession of unregistered sawed-off shotguns. They argued that the lower court erred in finding them guilty on counts two and three, claiming that their conduct did not cross the line from "mere preparation" to "attempt." However, the United States Court of Appeals, Second Circuit, affirmed the convictions of all three appellants on all four counts. The court found that the appellants had planned and prepared for the robbery, and had arrived at the bank with weapons and materials. The court concluded that their conduct went beyond mere preparation and constituted an attempt to commit the robbery. The government's evidence at trial consisted of testimony from an unindicted co-conspirator and FBI agents who surveilled the bank. The defendants conducted reconnaissance, purchased disguises and gloves, and were observed circling the bank before one of them was arrested and cooperated with the Government. On the day of the planned robbery, FBI agents observed the defendants' car parked near the bank, and one of the defendants was seen working on the car. The car was later seen parked in the same spot as before, but with the front license plate missing.

The appellants were found guilty of attempted bank robbery as they had taken substantial steps towards committing the crime. The court rejected their arguments that force, violence, or intimidation must be used before an attempted taking and that their case was different from a previous case. The court used the two-tiered inquiry from United States v. Mandujano to determine whether the defendants' conduct constituted an attempt to rob a bank. The Model Penal Code provides three ways in which a person can be guilty of attempted crime and also provides examples of conduct that may be considered a substantial step. Renouncing criminal purpose can be an affirmative defense against attempted crime, but this defense does not affect the liability of any accomplices who did not renounce their criminal purpose.

The Model Penal Code requires a substantial step in a course of conduct designed to accomplish a criminal result to constitute an attempt, which broadens the scope of attempt liability. The Mandujano test, based on this standard, was applied to determine that the appellants' attempted bank robbery convictions were proper. The court affirmed the lower court's ruling that the appellants' actions constituted a "substantial step" towards the planned crime. The convictions for attempted bank robbery were upheld. The court also affirmed the lower court's ruling that the FBI agents had probable cause for the arrests and search of the Lincoln, and that appellant Scott's conviction for violating 26 U.S.C. § 5861(d) was proper under the aiding and abetting theory or the Pinkerton theory. Other points raised by the appellants were not significant.