## Facts

- Two masked men in dark clothing robbed a Zaxby’s restaurant in Goose Creek, South Carolina, around midnight on December 24, 2011, using a gun and a knife.
- An assistant manager was shot during the robbery, and another victim was cut with a knife while the assailant took his wallet.
- Police gathered evidence including a scent trail leading away from the scene, DNA recovered from a ski mask and a firearm, items seized under a search warrant, and information that Donte Samar Brown had confessed to committing the robbery with Christopher Wilson.
- Wilson was subject to GPS ankle monitoring at the time; monitoring records indicated Wilson’s presence at the restaurant during the robbery.
- Wilson pled guilty before Brown’s trial.
- At Brown’s trial, the State offered Wilson’s GPS monitoring records through probation agent Steward Powell, who described generally how ankle monitors work and asserted GPS data is accurate and used in court “all the time.”
- Brown objected that the GPS records were not properly authenticated; the trial court overruled the objection and admitted the records.
- Brown was convicted, and the court of appeals affirmed.

## Issues

1. Whether GPS ankle-monitoring records are properly authenticated when the State relies primarily on generalized testimony that GPS data is accurate and commonly used in court, without a specific foundation for the particular records offered.
2. If the GPS evidence was admitted in error, whether the error was harmless beyond a reasonable doubt in light of other evidence of guilt.

## Decision

- The Supreme Court of South Carolina held the State failed to properly authenticate the GPS ankle-monitoring records; admitting them was error.
- The court concluded the error was harmless beyond a reasonable doubt because the remaining evidence of guilt was overwhelming.
- The court affirmed the court of appeals’ decision in result, leaving Brown’s convictions intact.

## Legal Principles

- Authentication requires evidence sufficient to support a finding that the proffered item is what its proponent claims it is.
- For electronic or technologically generated records, authentication generally requires a foundation addressing how the system produces, stores, and retrieves the data, and providing assurance of the integrity of the specific records offered.
- A witness’s conclusory assertion that a technology is accurate because it is used in court “all the time” is insufficient to authenticate specific GPS monitoring records.
- Erroneous admission of evidence may be affirmed if the appellate court determines the error was harmless beyond a reasonable doubt given the strength of the remaining evidence.

## Conclusion

The court ruled that GPS ankle-monitor data must be authenticated with a case-specific evidentiary foundation rather than generalized assurances of accuracy, but it affirmed the convictions because the improperly admitted GPS records did not affect the verdict in light of substantial independent evidence linking Brown to the robbery.


State v. Brown, 424 S.C. 479, 818 S.E.2d 735 (S.C. 2018)