someone's deceased foot. avis called cari's mom nancy. >> nancy was able to email a few pictures, and sure enough, cari has that same tattoo on her left foot. >> reporter: wow. >> identical. >> reporter: and remember the yin yang tattoo mentioned in one of those possibly confessional emails? lo and behold, it turns up on a picture? >> yeah. >> reporter: of a dead body? >> yeah. >> reporter: holy cow. >> that was cari's too. the tattoo parlor kept a record. >> my first thought when i saw those photographs was that this defendant had taken a trophy, or trophies of the person she had killed. >> reporter: the motive, a very old one, jealousy. >> it was really all about