## Facts

- Three men were shot and killed on a Chicago porch in the early morning of July 2, 1983.
- The prosecution argued the killings were gang-related retaliation involving the Latin Disciples and a prior juvenile killing of a gang member by one victim.
- Fernando Zayas was tried in the Circuit Court of Cook County, convicted of three counts of murder, and sentenced to three concurrent terms of life imprisonment without parole.
- The prosecution relied heavily on testimony from contested witnesses, including a former gang member who said Zayas confessed at a party the day after the murders; the party and confession were not independently corroborated.
- A police detective tried to recall a license plate number connected to a car near the scene, underwent hypnosis to “refresh” his memory, and then testified at trial to a post-hypnosis plate recollection that more closely resembled the number linking Zayas to the case.
- Zayas presented an alibi and attacked the reliability of the prosecution’s witnesses, including the hypnotically refreshed testimony.
- The appellate court affirmed; the Illinois Supreme Court allowed further review.

## Issues

1. Whether a witness other than the defendant may testify to the extent the witness’s recollection was enhanced through hypnosis.
2. Whether admitting a non-defendant witness’s post-hypnosis recollection requires reversal when the prosecution’s case is not otherwise overwhelming.

## Decision

- The Illinois Supreme Court reversed the appellate and trial court judgments and remanded for a new trial.
- The court held that a non-defendant witness may not offer testimony to the extent it is enhanced through hypnosis.
- The court concluded the detective’s post-hypnosis license-plate testimony was improperly admitted.
- The court found the error was not harmless because the hypnotically enhanced evidence provided concrete support for a prosecution case that depended on disputed witness credibility.

## Legal Principles

- Hypnotically enhanced recollections from non-defendant witnesses are inadmissible to the extent the hypnosis produced new details or changes in memory.
- A previously hypnotized witness is not automatically disqualified; the witness may testify to matters shown to have been known and recorded before hypnosis.
- The risk of suggestion, confabulation, and inflated confidence associated with hypnosis can substantially reduce the effectiveness of cross-examination and mislead the factfinder.
- When improperly admitted hypnotically enhanced testimony supplies key corroboration in a close case, reversal and a new trial are required.

## Conclusion

Illinois law bars non-defendant witnesses from testifying to memory content produced or altered by hypnosis; because the jury heard a detective’s post-hypnosis license-plate recollection and that evidence materially bolstered a contested prosecution case, the murder convictions were reversed and the case was remanded for a new trial.


People v. Zayas, 546 N.E.2d 513 (Ill. 1989)