>> i needed to go to the bathroom. i came back to his bedside and was stunned in the sense that he wasn't breathing. >> reporter: on november 7th, 2011, dr. conrad murray is found guilty of involuntary manslaughter and sentenced to four years in prison. but it doesn't end there. michael jackson's mother and children are bringing a wrongful death lawsuit against aeg, the concert promoter for jackson's doomed comeback tour. katherine jackson says aeg is to blame for the loss of her son. the whole case may hinge on an e-mail written just 11 days before michael jackson's death. it could be a smoking gun. in the e-mail, aeg's ceo tells the show's director to remind dr. murray what is expected of him and that aeg is paying his salary. jackson's family believes aeg pressured murray, even threatened his $150,000 a month