793 F.3d 703
7th Cir.2015Background
- Mackin was charged with being a felon in possession of a firearm; police recovered a gun and Officer Brown completed a continuity slip when placing it into evidence.
- The government produced an incomplete continuity slip in discovery (mostly blank, no signatures); at trial it produced a different, complete continuity slip with signatures and entries showing ATF custody.
- Mackin relied on the incomplete slip as his primary defense (after the court rejected a duress instruction) to challenge chain of custody and the firearm’s interstate-commerce nexus.
- When the complete slip appeared mid-trial, Mackin moved for a mistrial, arguing a Rule 16 discovery violation and prejudice; the district court denied the motion but allowed both slips into evidence.
- The jury convicted Mackin; on appeal the Seventh Circuit found the government violated Rule 16 by failing to provide the correct continuity slip and held Mackin was prejudiced by the belated disclosure.
- The court vacated the conviction and remanded for further proceedings.
Issues
| Issue | Plaintiff's Argument | Defendant's Argument | Held |
|---|---|---|---|
| Whether the government violated Fed. R. Crim. P. 16 by disclosing an incomplete continuity slip but not the complete form | Mackin: once government produced an incomplete slip, Rule 16 required disclosure of the complete, accurate version and supplementation | Government: had no reason to think chain-of-custody would be material and thus no duty to disclose the complete slip | Court: Violation occurred—once government disclosed the incomplete slip it had a duty to provide the correct, complete form or supplement discovery |
| Whether Mackin was prejudiced by the late disclosure such that mistrial was required | Mackin: he was unduly surprised, could not prepare or plea intelligently, and his only defense was undermined by belated evidence | Government: Mackin could alter strategy mid-trial and was not unfairly prejudiced | Court: Prejudice established—defense strategy and plea options were materially affected; mistrial should have been granted |
| Appropriate remedy for the Rule 16 violation | Mackin: conviction should be vacated and case remanded for new proceedings | Government: denial of mistrial was proper; any error harmless | Court: Denial of mistrial was an abuse of discretion; conviction vacated and remanded |
| Relevance of chain-of-custody discovery when the government later seeks to use the evidence at trial | Mackin: chain-of-custody documents are material when the defense challenges possession or interstate nexus | Government: not always discoverable absent indication defense will rely on them | Court: Once government elects to disclose a version of material evidence, the defense may reasonably rely on its accuracy and the government must supplement under Rule 16(c) if additional discoverable material exists |
Key Cases Cited
- United States v. Lee, 573 F.3d 155 (3d Cir. 2009) (failure to disclose material on a government document mid-trial prejudiced defendant and warranted mistrial)
- United States v. De La Rosa, 196 F.3d 712 (7th Cir. 1999) (standard of review and prejudice requirement for Rule 16 sanctions)
- United States v. Tatum, 548 F.3d 584 (7th Cir. 2008) (chain-of-custody affects the weight of firearm evidence)
- United States v. Noe, 821 F.2d 604 (11th Cir. 1987) (failure to disclose discoverable evidence can require a new trial when defense strategy was shaped by the omission)
- Muniz-Jaquez v. United States, 718 F.3d 1180 (9th Cir. 2013) (nondisclosure can deprive defendant of the ability to make informed plea decisions)
- United States v. Alvarez, 987 F.2d 77 (1st Cir. 1993) (prejudice where nondisclosure impaired plea strategy)
- United States v. Pascual, 606 F.2d 561 (5th Cir. 1979) (use of undisclosed evidence seriously prejudices defendants' plea decisions)
- Lafler v. Cooper, 566 U.S. 156 (U.S. 2012) (criminal justice predominantly plea-based; defendants lose substantive plea opportunities when unaware of government evidence)