You know why this happen? Its BECAUSE Children's Protective Services isn't interested in PROTECTING Children. Its interested in getting paid by the States' who get Federal Monies for every child that is placed in a Foster Home. The more time they can transfert hat child from foster home to foster the more monies that County's Children's Protective Services recieves. Even the Social Worker who places the child gets upwards of a $6,000 bonus!. If the child is adopted the Social Serivces Agency gets paid BIG BUCKS.
I don't know if the "Vale of Glamorgan" is a private organization or some sort of government entity in the UK. In the US, state children's services agencies may get "more money" when they adopt out kids, but it's not the same as, say, Exxon getting more money. As a private company, when Exxon gets more money it can pass it out in the form of executive raises and perks to its employees. A state agency, on the other hand, cannot give itself raises and new vehicles and building renovations - all those things can only be given by the state. So the "more money" the state agency gets can really only be used for operational expenses.
This case took place in the UK; but if the UK is anything like the US, then once a person turns 18, his juvenile criminal record is completely sealed (except for offenses where the child was tried "as an adult") and can never be opened, used, referred to or considered by the government ever again. I don't see why a social services agency would be "adopting out" an 18-year-old in the first place, as 18-year-olds are legal adults here...but if they did, in the US they would most likely be prevented BY LAW from disclosing the person's juvenile criminal history - sexual or otherwise.
And as I understand it, the UK doesn't try children "as adults" for any crime; so if the UK also seals juvenile criminal records, that might be the meat and potatoes of this situation. Even the newspaper article itself says that it's not permitted to give the accused's name. What you have is an agency that through some omission or miscommunication may have thought it wasn't allowed to disclose the perp's childhood history of abusing others. It wouldn't even surprise me if the very social worker who filed the papers was completely unaware of that history.
If all the above speculation is true, then perhaps it's time to re-examine the notion of sealing juvenile criminal records. Perhaps exceptions should be made for sexual offenses...although there you run into the problem of "punishing a kid for life" - a five year history of offenses means this person abused his first victim at the age of thirteen. How many people would want to sentence a thirteen-year-old to an entire lifetime of being labeled a sexual predator? Do we know for certain that by doing so we could prevent a situation like this one? If we don't, you're going to find a lot of resistance. It's a very tough decision to have to make.