They ran Crimewatch appeals and reconstructions, carried out offenderprofiling, compiled maps of where the burglaries happened and released a photofit of a man in a balaclava.
Criminologist Prof David Wilson of Birmingham City University, who once worked on the sex offender treatment programme at Grendon prison, says psychological profiling can indicate whether such a criminal is less likely to re-offend - but ultimately, the nature of the offence makes it impossible to be absolutely certain.