A federal defendant received an enhanced sentence under the Armed Career Criminal Act after the judge determined that prior offenses occurred on different occasions. The Supreme Court held that the Fifth and Sixth Amendments require a unanimous jury to make that factual determination beyond a reasonable doubt. Whether offenses were committed on separate occasions can depend on disputed facts about timing, location, and relationship, and it increases the statutory sentencing range. The narrow exception allowing judges to identify the fact of a prior conviction did not extend to this additional historical inquiry. The judgment was vacated and the case remanded.