Amanda Knox interview attracts 8.5 million viewers, one of Diane Sawyer's lower-rated 'gets'

If ABC was expecting boffo ratings for Diane Sawyer's exclusive interview with Amanda Knox, it did not happen. "Murder. Mystery. Amanda Knox Speaks -- A Diane Sawyer Exclusive" attracted an average of 8.5 million viewers at 10 p.m. Tuesday -- about 800,000 viewers ahead of CBS's original "Golden Boy" episode in the same hour.