That bit about 'telling the police if people are innocent'?? That's cover for parallel construction.
They told police in secret who to arrest and for what and where to look. And the police did that, found the 'evidence' they were told to find, and created the fake evidence trail for the court.
And maybe it was evidence and maybe it was planted. Since the court never examines the real evidence we won't know. All we know is the police lied in court to cover the mass surveillance. So they were complicit in hiding the crime from Parliament.