Investigators are looking into whether Prince died from an overdose and whether a doctor was prescribing him drugs in the weeks before he was found dead at his home in suburban Minneapolis, a law enforcement official told The Associated Press. The official said Thursday that among the things investigators are looking at is whether a doctor was with Prince on a plane that made an emergency landing in Illinois less than a week before the star died. The law enforcement official has been briefed on the investigation and spoke to the AP on condition of anonymity because he was not authorized to speak to the media.