The Metropolitan Police committed "bad errors" and "missed opportunities" to stop the killer of Rachel Nickell before her death, a report has said.

Serial rapist Robert Napper admitted killing Ms Nickell on Wimbledon Common, south-west London in 1992.

The Independent Police Complaints Commission (IPCC) found Napper, 42, was identified as a threat to women in the mid-1980s.

The Met said it "regrets" that Napper "was able to carry out dreadful acts".

Colin Stagg, the man wrongly accused of murdering Ms Nickell said he was considering through his solicitor whether to pursue his own complaint through the IPCC.

His solicitor Alex Tribeck said his client wanted to ensure that the "professional negligence" of the Metropolitan Police should never be repeated.
http://news.bbc.co.uk/1/hi/england/london/10216328.stm

So, it was police incompetence that led to Napper being able to commit this crime. And it led to the wrong man having to face the charges for many years.