Lil Twist, Justin Bieber's former sidekick, has been sentenced to a year behind bars after pleading no contest to beating and robbing Nickelodeon actor Christopher Massey. On the first day of his scheduled trial Wednesday, the 23-year-old rapper, whose real name is Christopher Lynn Moore, entered the plea in Los Angeles County Court . The plea wasn't negotiated with prosecutors, who objected to it. Prosecutors said the charges stemmed from an occasion two years ago when "Zoey 101" star Christopher Massey asked Moore to leave a party. They say Moore slapped Massey before leaving, then returned with others and beat the actor.