two years after hailey's birth, she decided to invite 16-year-old foster child sabrina zunich into her home and to make sabrina part of the family. >> i met sabrina almost immediately when she came to the house. i remember her saying i finally have a family. >> everything was going really well. she fit right into the family. lisa, i mean, couldn't talk highly enough about her. >> but the happy timesro would come to a catastrophic end on that november back in 2012 when lisa knoefle was brutally stabbed in her home. >> when i heard it was lisa and who did it, i couldn't believe it. it was like, you're kidding me. >> a devoted mom attacked in her own home, enough to shock any family but the story behind this crime would leave them nothing less than shattered. >> the blade was actually bent. i just started shaking my head because i couldn't -- it takes a lot to bend a knife blade. >> who could have felt enough rage to do that and why? is that ice cream? no, it's, uh breyers gelato indulgences. it looks like ice cream. it's not. can i have some? you really wouldn't like it. it's got