Mr Yates also admitted police could have done more to catch Napper and prevent further crimes, in particular the murders of Samantha and Jazmine Bissett.
Furthermore, even the most intense space combat can be paused with a touch of the space bar, making it perfect for the heavy cougher or febrile napper.
Mr Ellam, who suffered post-traumatic stress disorder, thinks detectives could have caught Napper for the spate of up to 70 sex offences in south-east London parkland, which became known as the Green Chain rapes, a year earlier.