Just before his highly anticipated Super Bowl halftime show, R&B superstar Usher opens up. It's going down in Sin City, where his residency has dominated the strip. And we revisit his career - from baby-faced church choirboy to the reigning king of R&B.

For 20 years, Scott Peterson has been behind bars, found guilty of murdering his pregnant wife Laci and their unborn son. Could evidence brought to light by the Los Angeles Innocence Project set one of America's most notorious convicted killers free?