The full episode is here.
If you missed it on ABC's 20/20, it's worth watching. The death penalty for the offenders wouldn't disturb me at all. As Katie's mother said, it's hard to think of such people as human beings. The main offender got two life sentences, which means that he will spend at least 16 years in prison. The other could be out in 6. Britain has a funny way of doing math these days.
What Katie used to look like, in the days when, says she, "I used to be the most important person in my life.":