## Facts

- U.S. Fish and Wildlife Service agents conducted an undercover operation after meeting Edward Engler and an associate at a trapper’s gathering in Pennsylvania in September 1982.
- Between May 1983 and January 1985, Engler repeatedly sold undercover agents migratory birds or bird parts protected by the Migratory Bird Treaty Act (MBTA).
- During the same period, Engler and his associate also sold dynamite to the agents, leading to federal explosives charges.
- A grand jury returned multiple indictments charging MBTA offenses (including a felony provision, 16 U.S.C. § 707(b)(2)) and explosives-related offenses (including 18 U.S.C. §§ 2, 842(b)).
- A jury convicted Engler on MBTA and explosives counts; after trial, the district court dismissed the MBTA felony charges on due process grounds, reasoning that imposing felony liability without mens rea was unconstitutional.

## Issues

1. Whether Engler was entrapped as a matter of law, requiring reversal of his convictions.
2. Whether the undercover operation involved government conduct so outrageous as to violate due process and bar prosecution.
3. Whether an asserted evidentiary error at trial required reversal.
4. Whether 16 U.S.C. § 707(b)(2) is unconstitutional under the Due Process Clause because it imposes felony penalties without requiring proof of mens rea.

## Decision

- The Third Circuit affirmed Engler’s convictions and sentences, rejecting entrapment, due process, and evidentiary challenges.
- The court held entrapment was not established as a matter of law because the record supported predisposition, including repeated voluntary sales over an extended period.
- The court held the agents’ conduct did not rise to the level of “outrageous” behavior that would violate fundamental fairness; the operation primarily provided opportunities to commit crime.
- The court found no reversible evidentiary error under the governing standard and concluded any alleged mistake did not affect substantial rights.
- On the government’s cross-appeal, the court reversed the post-trial dismissal and held MBTA § 707(b)(2) constitutional as a strict-liability felony.

## Legal Principles

- Entrapment (subjective test) requires government inducement and lack of predisposition; repeated voluntary criminal transactions over time are strong evidence of predisposition and ordinarily defeat entrapment as a matter of law.
- Due process bars prosecution for “outrageous” government conduct only in exceptional cases; standard undercover techniques that offer an opportunity to commit crime generally do not violate due process.
- Trial evidentiary rulings are reviewed for abuse of discretion; relief requires a showing that the ruling affected substantial rights.
- Congress may, consistent with due process, create strict-liability offenses within public-welfare regulatory schemes, including in wildlife protection.
- The fact that Congress labels an offense a felony does not alone impose a constitutional requirement of a mens rea element; commercial trafficking in heavily regulated wildlife can be penalized as a strict-liability felony under the MBTA.

## Conclusion

The Third Circuit upheld Engler’s wildlife and explosives convictions and held that the MBTA’s felony provision, § 707(b)(2), may constitutionally impose strict criminal liability for commercial sales of protected migratory birds, while also rejecting claims of entrapment, outrageous government conduct, and reversible evidentiary error.


United States v. Engler, 806 F.2d 425 (3d Cir. 1986)