(CNN) -- In a soft voice, teenager Austin Sigg confessed in gruesome detail how he snatched a 10-year-old girl from his Colorado neighborhood and dismembered her.
But what Sigg could not explain to police detectives is why.
One day after Thanksgiving last year, my mother, brother, cousin and I gathered in my 87-year-old grandmother's room at the nursing home. We knew it would be one of the last times we would see her alive. She knew it, too.