## Facts

- Providence police attempted to arrest Francisco A. Collado in a parking lot in the early morning of May 24, 1990, and an officer saw Collado drop a bag while fleeing.
- Another officer retrieved the bag, transported it to the station, completed a seizure report, and turned it over to the police bureau that processes drug evidence.
- The bag contained thirty small baggies of cocaine and sixteen glassine packets of heroin bound with an elastic band and labeled “Fly High.”
- Because the processing office was closed overnight, standard procedure required placing the evidence through a mail slot into a locked safe and leaving the seizure report on top of the safe.
- The next morning, the evidence officer found the seizure report on the safe, opened the safe, and retrieved a clear plastic bag whose contents matched the seizing officer’s description.
- The government presented testimony establishing an uninterrupted chain of custody from retrieval from the safe through introduction at trial, with no indication of alteration.

## Issues

1. Whether the district court abused its discretion by admitting the plastic bag and its contents where Collado challenged authentication and chain of custody under Federal Rule of Evidence 901(a).

## Decision

- The First Circuit affirmed the convictions.
- The court held the government established a reasonable probability that the exhibit was what it was claimed to be.
- The court ruled that speculative or minor gaps in chain of custody generally affect the weight of the evidence, not its admissibility, absent proof of tampering or material alteration.
- The court found no abuse of discretion in admitting the bag and narcotics.

## Legal Principles

- Under Fed. R. Evid. 901(a), physical evidence is authenticated if the proponent shows a reasonable probability that the item is what the proponent claims.
- The proponent need not eliminate every conceivable possibility of substitution or tampering; the chain of custody must support a reasonable probability of no material alteration.
- Challenges based on theoretical access or incidental custody uncertainties typically go to the jury as issues of weight rather than admissibility.
- Courts may rely on a presumption that public officials properly discharge official duties when standard evidence-handling procedures are shown and there is no affirmative indication of irregularity.
- Trial-court determinations on authentication and chain of custody are reviewed on appeal for abuse of discretion.

## Conclusion

The court upheld admission of narcotics recovered after a foot chase because the government’s proof—officer observations, documented seizure handling, standard secure storage procedures, and lack of evidence of tampering—met Rule 901(a)’s reasonable-probability standard, leaving any remaining doubts for the jury.


United States v. Collado, 957 F.2d 38 (1st Cir. 1992)