## Facts

- Delaware State Police Detective Garland investigated child-pornography distribution on a peer-to-peer (P2P) gnutella network using a publicly available client and a search term associated with child pornography.
- The search results listed files with metadata, including file names, sizes, availability, and SHA-1 hash values.
- Garland identified a file with an explicit, graphic title describing sexual activity involving very young children and noted its SHA-1 value matched a hash he understood to correspond to a child-pornography video.
- Garland attempted to download the file and connected to a computer advertising the file from a specific IP address.
- Garland relayed information to Pennsylvania State Police Lieutenant Peifer, who obtained the file, confirmed it was child pornography, and traced the IP address to subscriber information linked to Stephen Miknevich’s residence.
- Police sought a Pennsylvania search warrant for Miknevich’s residence and computer based on an affidavit describing the P2P investigation, the explicit file name, the SHA-1 association with known contraband, and the IP-to-residence link.
- The affidavit did not attach the video and did not provide a detailed narrative description of the video’s visual content beyond the file title and hash identification.
- A Pennsylvania district justice issued the warrant; officers executed it, seized Miknevich’s computer, and found numerous images and videos of child pornography.
- After the search, Miknevich made oral and written admissions to officers.

## Issues

1. Whether the warrant affidavit provided a substantial basis for finding probable cause to search for child pornography despite not attaching the file or providing a detailed visual description of its contents.
2. If probable cause was lacking, whether evidence should nonetheless be admitted under the Leon good-faith exception.
3. Whether Miknevich’s sentence was cruel and unusual punishment in violation of the Eighth Amendment.

## Decision

- The Third Circuit affirmed the denial of suppression and affirmed the conviction and sentence.
- The court held the affidavit supplied a substantial basis for probable cause under the totality of the circumstances, relying on the investigative context, the explicit file name, and the SHA-1 hash association with known child pornography.
- Because probable cause existed, the court did not need to decide the Leon good-faith issue as an independent ground for admission.
- The court rejected the Eighth Amendment challenge on plain-error review, finding no gross disproportionality.

## Legal Principles

- Probable cause is a practical, common-sense determination assessed under the totality of the circumstances; reviewing courts give deference to the issuing magistrate and ask whether there was a substantial basis for the determination.
- In digital child-pornography investigations, an affidavit may establish probable cause through a combination of (i) explicit file names, (ii) explanation of investigative methods and context (including P2P querying using known child-pornography terms), and (iii) corroborating technical identifiers such as a SHA-1 hash linked to known contraband.
- The Fourth Amendment does not impose a categorical requirement that contraband images or videos be attached to a warrant application or that affidavits provide an exhaustive frame-by-frame narrative, particularly where the affidavit otherwise permits a reasonable inference of illegality.
- The Leon good-faith exception generally turns on whether officers’ reliance on a warrant was objectively reasonable; affidavits containing meaningful investigative detail are less likely to be treated as “bare bones.”
- Under Eighth Amendment proportionality doctrine, a sentence violates the Constitution only if it is grossly disproportionate to the offense; challenges raised for the first time on appeal are reviewed for plain error.

## Conclusion

The Third Circuit held that a search warrant for suspected child pornography was supported by probable cause where the affidavit described a targeted P2P investigation, identified an explicitly titled file, and linked it to a known SHA-1 hash and an IP address traced to the defendant’s residence, even without attaching the file or detailing its visual contents; the court also found no plain-error Eighth Amendment violation in the sentence.


United States v. Miknevich, 638 F.3d 178 (3d Cir. 2011)