## Facts

- Aaron Shaffer used Kazaa, a peer-to-peer file-sharing program that stores downloaded files in a “My Shared Folder” and makes them available to other users while the program is running.
- Shaffer downloaded child-pornographic images and videos and kept them in his Kazaa shared folder.
- Shaffer admitted downloading child pornography, storing it in his shared folder, and doing so in part to obtain Kazaa-provided incentives when others downloaded files from him.
- Shaffer often left his computer running while he was away to permit downloads by other Kazaa users.
- A federal agent accessed Shaffer’s shared folder using Kazaa and downloaded files later determined to be child pornography.
- Based on the downloads, agents obtained and executed a search warrant at Shaffer’s residence, seized his computer, and found additional illicit material.
- Shaffer confessed he was the sole user of the computer and acknowledged the presence of child pornography in his shared folder.
- At trial, Shaffer conceded possession but argued he did not “distribute” because he only passively made files available rather than actively transmitting them.

## Issues

1. Whether a defendant “distributes” child pornography under 18 U.S.C. § 2252A(a)(2) by knowingly placing files in a Kazaa shared folder that others can access and actually download.
2. Whether the district court abused its discretion by limiting defense expert testimony addressing Shaffer’s state of mind and intent.
3. Whether the district court abused its discretion by admitting Fed. R. Evid. 404(b) evidence, including a narrative titled “House of Incest,” to prove intent or knowledge.
4. Whether the jury instructions on distribution and related elements misstated the law or misled the jury.

## Decision

- The Tenth Circuit affirmed Shaffer’s convictions and sentence.
- The court held that Shaffer’s knowing placement of child-pornography files in his Kazaa shared folder, combined with awareness that others could and did download them, supported a finding of “distribution” under § 2252A(a)(2).
- The court held the district court acted within its discretion in restricting expert testimony that would have addressed Shaffer’s intent and encroached on the jury’s role.
- The court held the admission of “House of Incest” and other Rule 404(b) evidence was not an abuse of discretion because it was relevant to intent and accompanied by a limiting instruction.
- The court held the jury instructions, viewed as a whole, contained no reversible error; one instruction proposed by Shaffer was more favorable than required.

## Legal Principles

- “Distribution” under 18 U.S.C. § 2252A(a)(2) can be proven when a defendant knowingly makes child-pornographic files available for download through a peer-to-peer shared folder and files are in fact obtained by others; manual, one-to-one sending is not required.
- Evidence supporting distribution may include the defendant’s knowledge of how the software shares files, conduct facilitating downloads (e.g., leaving the computer on), and proof that downloads occurred.
- Trial courts may limit expert testimony that effectively opines on the defendant’s mental state or draws ultimate conclusions reserved for the jury; appellate review is for abuse of discretion.
- Rule 404(b) evidence may be admitted to prove intent or knowledge (not propensity) when relevant and properly constrained by a limiting instruction; evidentiary rulings are reviewed deferentially.

## Conclusion

The Tenth Circuit held that knowingly making child-pornography files available for others to download via a peer-to-peer shared folder constitutes “distribution” under § 2252A(a)(2), and it found no reversible error in the district court’s limits on expert testimony, admission of Rule 404(b) evidence, or jury instructions.


United States v. Shaffer, 472 F.3d 1219 (10th Cir. 2007)