Why did it take so long to bring Britain's most prolific serial rapist to justice?

John Worboys preyed on the women of London, drugging, raping and sexually assaulting over 100 victims in his taxi cab between 2000 and 2008.
This show is not currently available on BBC Select but browse through the below titles for more documentaries available to stream on BBC Select.
Catching The Black Cab Rapist on BBC Select
In this chilling true crime documentary on BBC Select, some of his victims and the police team that finally cracked the case discuss flaws in the original investigation.
Why did it take so long to bring Britain’s most prolific serial rapist to justice?