Dallas Cowboys defensive end Aldon Smith had already been suspended from the NFL several years when his ailing grandmother implored him to change his life before she died of complications from Lou Gehrig's disease.
Before that, Smith was a rising star in San Francisco when his legal troubles began in 2013.
The Raiders still had his contractual rights two years ago before releasing Smith after San Francisco police issued an arrest warrant over allegations of domestic violence.
His path to Dallas is special and unique, said McCarthy, who faced Smith and San Francisco four times in a span of two seasons as Green Bay's coach.
San Francisco reached the Super Bowl in his second season, losing to Baltimore, and played in the NFC championship game each of his first three years.