US v. Hall: Hall was charged with possession of marijuana and guns. Said guns and marijuana were found in a locked bedroom in the house where Hall appeared to be living. However, the door was locked when police searched the home and Hall did not have the key. Furthermore, none of the items seized from the locked bedroom had Hall's fingerprints and no one would testify that the items belonged to Hall. What the Government did have was several of Hall's prior convictions - for both simple possession of marijuana and possession with intent - which were admitted at trial as 404(b) evidence. The district court admitted the convictions even though it wasn't "sure Rule 404(b) was drafted to be that broadly construed" but it was "bound . . . to follow the Fourth Circuit law" - in this case, an unpublished decision from 2013. Hall was convicted on all counts at trial.
On appeal, the Fourth Circuit reversed his convictions, 2-1. Although Hall presented multiple issues, the only one the court resolved was whether the prior convictions were properly admitted under Rule 404(b). After a lengthy discussion of the nature of constructive possession (the only avenue open to the Government to secure the conviction) and the Government's burden to show how 404(b) evidence is relevant to the issues at trial, the court concluded that the Government failed to meet its burden. As a result, the district court abused its discretion by admitting the evidence. Along the way, the court shot down the Government's attempt to review the issue for plain error and the district court's reliance on unpublished - therefore non-binding - authority as the basis for its decision. The court also spent a lengthy amount of time responding to the dissent. The error in admitting the convictions was not harmless and required the reversal of Hall's convictions.
As to the dissent, Judge Wilkinson argued that the district court not only didn't abuse its discretion but made the right call in admitting the evidence. He takes the majority to task for not providing a full picture of the facts (thus making it look like Hall's connection to the drugs was more tenuous than it really was). More notably, he accuses the majority of engaging in the "encroachment of overactive appellate judging on the roles of district courts, juries, and advocates in the conduct of a trial." He also argued that the majority had declared that prior drug convictions were almost never relevant under Rule 404(b).