LOS ANGELES (AP) -- Heath Ledger's sociopathic reinvention of Batman bad guy the Joker in "The Dark Knight" has earned him the supporting-actor honor at the Screen Actors Guild Awards. His co-star Gary Oldman has accepted the prize on behalf of the late actor. The win puts the late actor a step closer to becoming just the second performer to win a posthumous Academy Award. Oscar buzz has been flying over Ledger's performance since before his death just over a year ago from an accidental overdose of prescription drugs. With the SAG win and the Golden Globe, Ledger now looks like a virtual lock to receive the supporting-actor Oscar on Feb. 22. ——— On the Net: http://www.sagawards.com