I guess Varina and Freedox were with Richard at all times from Sept. 12, 2000, when he was paroled, until June 14, 2002. That's how they know he never used drugs. They were in that bed (must've been a king-size; maybe Damon and Brenda were there too) with the Riccis the night of June 4-5, too b/c of course there is just no question that Richard was home in bed with his wife. We know what a homebody he was.
Tom is suspicious, and weird, but I've never heard that he walked around inside anyone else's house at night w/o permission, gazing at sleeping young women and helping himself to cash from their dressers. If I hear he has done such a thing, that's different. Also, to my knowledge, Heidi has never forged a check and done time for it--as Angela has.