## Facts

- Multiple shootings occurred on October 8, 2004, in connection with Ernie’s Café in New London, Connecticut.
- William Robinson was shot at the bar; later, Cedric Williams and Terry Ross were found shot to death in a Volvo in a nearby parking lot.
- Ballistics evidence linked the shootings.
- Several eyewitnesses identified Brady Guilbert as the shooter; identifications were made under stressful conditions and included both acquaintances and a stranger.
- A jury convicted Guilbert of capital felony, two counts of murder, and first-degree assault; he received life imprisonment without possibility of release plus twenty years.
- The defense sought to present expert testimony from Dr. Charles A. Morgan III on factors affecting eyewitness reliability (e.g., stress, weapon focus, cross-racial identification, post-event information).
- The trial court excluded most of the proffered expert testimony, relying on prior Connecticut cases that disfavored such evidence.
- Guilbert appealed, challenging the exclusion of the expert testimony and the denial of mistrial/new trial motions based on the state’s delayed disclosure of allegedly favorable evidence.

## Issues

1. Whether qualified expert testimony on the fallibility of eyewitness identification is admissible under Connecticut’s expert-evidence standard and whether prior precedent categorically disfavoring such testimony should be overruled.
2. Whether the trial court abused its discretion by excluding the defense expert’s eyewitness-reliability testimony and, if so, whether the error required reversal.
3. Whether delayed disclosure of allegedly favorable evidence warranted a mistrial or a new trial on due process grounds.

## Decision

- The Connecticut Supreme Court overruled the prior cases that generally disfavored expert testimony on eyewitness identification.
- The court held that qualified expert testimony on eyewitness fallibility is admissible under the Porter framework when it would aid the jury’s evaluation of identification evidence.
- The trial court improperly excluded portions of the defense expert’s testimony, but the error was harmless.
- The court affirmed the denial of mistrial and new trial motions based on delayed disclosure, concluding the defendant was not deprived of a fair trial.
- The judgments of conviction were affirmed.

## Legal Principles

- Expert testimony on the fallibility of eyewitness identification may be admitted when (1) the witness is qualified, (2) the subject matter is reliable under Porter, and (3) the testimony would assist the jury in evaluating the identification evidence.
- Courts should not presume that jurors understand empirically supported limits on eyewitness accuracy; many relevant effects may be counterintuitive (including stress effects, weapon focus, cross-racial identification error risk, and post-event influence).
- Such expert testimony does not improperly decide credibility; it may provide scientific principles that help jurors assess identification evidence.
- Cross-examination, argument, and jury instructions may address eyewitness risks, but they do not justify a categorical rule excluding helpful expert testimony; trial courts retain case-specific discretion.
- Erroneous exclusion of expert testimony warrants reversal only if it creates a reasonable probability of a different verdict; corroboration and multiple identifications can render the error harmless.
- A late-disclosure due process claim fails absent a showing that the timing undermined confidence in the verdict or otherwise denied a fair trial.

## Conclusion

The Connecticut Supreme Court held that qualified expert testimony on eyewitness-identification fallibility is generally admissible when it would assist the jury, overruled contrary precedent, found partial exclusion of the defense expert to be harmless on the record, and affirmed the convictions and the denial of relief based on delayed disclosure.


State v. Guilbert, 306 Conn. 218, 49 A.3d 705 (Conn. 2012)