Bruce Ivins, the Army scientist accused of masterminding the 2001 anthrax attacks, e-mailed himself last year saying he knew who the killer was, according to court documents unsealed Wednesday. Yes! Yes! Yes!!!!!!! I finally know who mailed the anthrax letters in the fall of 2001. I've pieced it together!" Ivins wrote in the e-mail dated Sept. 7, 2007, according to an FBI affidavit. "I'm not looking forward to everybody getting dragged through the mud, but at least it will all be over," Ivins allegedly wrote. "Finally! I should have it TOTALLY nailed down within the month. I should have been a private eye!!!!" The e-mail did not say who Ivins thought was the anthrax killer. Ivins committed suicide in July as prosecutors prepared to charge him in the mailings that killed five people and sickened 17 others. The e-mail was signed "bruce" and sent from an America Online address by the name of "KingBadger7." Authorities said it was one of at least six e-mail addresses registered to Ivins. The FBI affidavit was included in the final batch of court documents to be released by the government that shows how prosecutors built their case against Ivins. Ivins' lawyer, Paul Kemp, has maintained that Ivins was innocent and has predicted the scientist would have been cleared if the case had gone to trial. It was not unusual for Ivins to e-mail himself, according to the FBI document. "In addition, Ivins has sent at least one other e-mail to himself that details his opinion of who may have been the anthrax mailer," the affidavit states.