## Facts

- Federal agents investigated Michael Anthony Weaver for drug trafficking beginning in 2008 and obtained evidence from his then-residence, including over 500 grams of marijuana, cash, and packaging materials.
- A federal arrest warrant issued in 2010; Weaver was later indicted on numerous drug and money-laundering counts.
- In 2012, agents located Weaver at a new apartment and went there with an arrest warrant only, not a search warrant for that residence.
- Officers knocked twice; within about a minute they announced “police” and attempted entry using a concierge-provided key, without informing Weaver they had an arrest warrant.
- Weaver braced the door; officers forced entry, arrested him inside, and observed indicators of marijuana (odor and bags in plain view).
- Based on those observations, agents obtained a search warrant and recovered several kilograms of marijuana, other drugs, and cash.
- Weaver was convicted of possession with intent to distribute marijuana; he challenged admission of the apartment evidence.

## Issues

1. Whether officers executing a valid arrest warrant at a suspect’s home violated the Fourth Amendment by failing to comply with the knock-and-announce requirement before forced entry.
2. Whether, in the arrest-warrant context, a knock-and-announce violation may trigger the exclusionary rule, requiring suppression of evidence later seized under a search warrant derived from the unlawful entry.

## Decision

- The court held the officers violated the knock-and-announce rule when they forcibly entered Weaver’s apartment to execute the arrest warrant.
- The court reversed the denial of Weaver’s suppression motion and remanded.
- The majority concluded suppression was an appropriate remedy because the knock-and-announce violation was a but-for cause of the observations that supported the later search warrant, the causal link was not attenuated, and deterrence benefits outweighed exclusion costs.
- A dissent would have applied the Supreme Court’s knock-and-announce remedial analysis to bar suppression and viewed causation as too attenuated.

## Legal Principles

- The Fourth Amendment’s reasonableness requirement generally includes a duty to knock and announce “presence and authority” before forced home entry to execute a warrant, absent a recognized exception.
- An arrest warrant authorizes seizure of the person but does not, by itself, confer authority to search the home beyond what is necessary to effectuate the arrest.
- Suppression analysis considers (1) but-for causation, (2) whether the connection between illegality and discovery is too attenuated, and (3) whether deterrence gains justify the social costs of exclusion.
- Where officers enter a home under an arrest warrant without proper knock-and-announce compliance, and the entry produces observations that generate probable cause for a search warrant, suppression may be warranted if lawful compliance could have enabled a threshold arrest without home entry.

## Conclusion

The D.C. Circuit held that a knock-and-announce violation during execution of an arrest warrant at a residence can require suppression of evidence when the unlawful entry directly causes discovery of the evidence later seized, and exclusion is justified under causation and deterrence-cost balancing principles.


United States v. Weaver, 808 F.3d 26 (D.C. Cir. 2015)