London's top policeman has called upon all residents to install security cameras in their homes to help officers do their job.
Sir Bernard Hogan-Howe told LBC radio that CCTV cameras positioned at face-level inside rooms would make investigating crimes such as burglary and theft easier.
There were almost 50,000 home burglaries in London during the 12 months to January, a year on year fall of 14%.
That is because many of the current crop of security cameras capture only the tops of intruders' heads, due to being located near ceilings.
Modern facial-recognition technology means it is possible to track down offenders more effectively if there is an image of their face.
"What we need to be able to do is to compare that photograph with the images we have of people committing a crime," Hogan-Howe told listeners.
"Taking the tops of their heads is not that helpful for facial recognition which relies on the eyes and the configuration of the area around the nose and the mouth. So we're trying to get people to, ideally, add another camera at face level."