A law enforcement official says federal prosecutors have dropped the investigation into how Heath Ledger obtained two painkillers that contributed to his overdose. The official says prosecutors in the U.S. attorney's office in Manhattan bowed out "because they don't believe there's a viable target." The official spoke to The Associated Press on condition of anonymity because no charges have been filed. The decision comes in the wake of news reports that the Drug Enforcement Administration was pressuring actress Mary-Kate Olsen to speak to agents about the accidental overdose death of her close friend.

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