Leonard Roberts has revealed the struggles he endured in his first series-regular acting role on the hit TV show “Heroes,” which he considers race-related. And former costar Ali Larter has issued an apology, noting that his account “absolutely doesn’t match my memory nor experience on the show,” which ran on NBC for four seasons from 2006 to 2010. “Drumline” star Roberts played D.L. Hawkins, husband to Larter’s Niki Sanders, in the first season of the series, which was a giant springboard to success for many in its cast, including Milo Ventimiglia, Zachary Quinto, Masi Oka and Hayden Panettiere. Roberts’ character was killed off, off-camera, after the first season.