7th Circuit analyzes staleness in computer searches, holds the doctrine should apply "only in the exceptional case"

In United States v. Seiver, No. 11-3716 (7th Cir. 2012), in an opinion by Judge Posner, the Seventh Circuit analyzed the issue of staleness as it relates to a finding of probable cause to search a computer. Noting that "modern computer technology and the usual behavior of its users" support the position that the probable cause was not stale, the conviction was affirmed.

The case concerned a search warrant for child pornography on the defendant's computer. A 13-year-old girl had uploaded a pornographic video of herself to the Internet, and the defendant later discovered and downloaded that video. He then uploaded stills from the video to a photo-sharing site and sent an album link to the girl's stepmother who alerted police. Law enforcement tracked the IP address to the defendant, but there was a seven month gap between the upload and the search of his home.

On appeal, the defendant argued "that there was no reason to believe that seven months after he had uploaded child pornography there would still be evidence of the crime on his computer." Here's a summary of the points of Judge Posner's opinion (which in itself is a well-condensed opinion and difficult to summarize):

1. The traditional issue with staleness is whether the defendant was a collector of child pornography and was "likely to have 'retained' or 'maintained' rather than 'destroyed' the ... images." However, this concern alone "reflects a misunderstanding of computer technology."
2. Posner then goes into great detail in discussing deleted files, overwriting data, and file recovery.
3. "'Staleness' is highly relevant to the legality of a search for a perishable or consumable object, like cocaine, but rarely relevant when it is a computer file. Computers and computer equipment are 'not the type of evidence that  rapidly dissipates or degrades (internal citations omitted).'"
4. After a file has been deleted, "it is possible that the deleted file will no longer be recoverable" ... [or] the computer will have been sold or physically destroyed." Despite these possibilities and the time interval, however, "rarely will they be so probable as to destroy probable cause ... for probable cause is far short of certainty."
5. "[I]t appears that few consumers of child pornography ... understand well enough how their computer’s file system works to grasp the importance of wiping or overwriting their deleted pornographic files or encrypting them securely if they want to avoid leaving recoverable evidence ... after they've deleted it." Though software to perform these tasks is readily available, its use "is surprisingly rare."
6. "[A]fter a very long time, the likelihood drops to a level at which probable cause ... can no longer be established." However, "seven months is too short."
7. Possession requires knowing possession, and images being in slack space may prevent the knowledge element. However, that does not eliminate probable cause "unless the statute of limitations on possession ha[s] expired."
8. "Only in the exceptional case should" staleness be used to strike down a search of a computer for child pornography.
9. "[F]uture changes in computer technology may alter" the staleness inquiry, "and judges as well as law enforcers must be alert to that possibility as well.