What all these cases illustrate to me, is how badly police forces are messing up on dealing with sex crimes, domestic abuse etc which can escalate to murder.
There is a heavy "people in glasshouses ..." aspect to this, especially as regards The Met, a force that is so corrupt and inept, with sex offenders within it's own ranks - that politicians have called for root and branch reform at a minimum, if not it's complete replacement.
it seems clear that CB operated as a sex predator in the Algarve over multiple years, if not Germany as well, unless we think he only does his breaking and entering / rapes while in Portugal
He never would have been caught, had he not been ratted out. But unfortunately that is all to common in the UK, US etc
I was reading about a guy who did a murder in the US, who would have been caught sooner, only they never processed the rape kit from his first rape ... Sigh