## Facts

- McBoyle transported a stolen airplane from Ottawa, Illinois, to Guymon, Oklahoma, knowing it was stolen.
- He was prosecuted under the National Motor Vehicle Theft Act, which criminalized interstate transportation of a stolen “motor vehicle.”
- The Act defined “motor vehicle” to include “an automobile, automobile truck, automobile wagon, motor cycle, or any other self-propelled vehicle not designed for running on rails.”
- A federal district court convicted McBoyle and imposed three years’ imprisonment and a $2,000 fine.
- The Tenth Circuit affirmed, and the Supreme Court granted review on whether the Act applied to aircraft.

## Issues

1. Whether an airplane qualifies as a “motor vehicle” under the National Motor Vehicle Theft Act’s definition, including “any other self-propelled vehicle not designed for running on rails.”

## Decision

- The Supreme Court reversed the conviction.
- The Court held that an airplane is not a “motor vehicle” within the meaning of the Act.
- Because the statute did not clearly cover aircraft, McBoyle’s conduct fell outside the criminal prohibition.

## Legal Principles

- Statutory terms are read according to their ordinary meaning; in common usage, “vehicle” primarily denotes a conveyance that moves on land.
- A general catch-all phrase following specific enumerated items is interpreted in light of the listed examples; here, the list pointed to land-based motor conveyances rather than aircraft.
- Congressional omission matters where a statute carefully enumerates covered items; the absence of any reference to aircraft supported exclusion.
- In criminal statutes, fair notice controls: conduct should not be treated as criminal unless the statute clearly warns that it is within the prohibition.
- Ambiguity in a penal statute is resolved against expanding liability beyond ordinary understanding (rule of lenity).

## Conclusion

The Court held that the National Motor Vehicle Theft Act did not criminalize interstate transportation of a stolen airplane because, in ordinary usage and statutory context, an airplane is not a “motor vehicle,” and criminal liability requires clear statutory notice.


McBoyle v. United States, 283 U.S. 25 (1931)