Oh they knew but ultimately who wants to trash their dead child to the public . Read they moved from Nottingham to london to for a 'fresh start' and he was part of a preventation programme obviously contradicts their innocent claim.
Anyway wash, rinse, repeat if the killers are juveniles it's 15 years in these increasingly soft prisons (soon be no bars in cells and a suggestion of laptops in a few years) and back out with significantly decreased prospects upon release when in their mid to late thirties life really is disposable.