BELLEVILLE (ONTARIO) - BY DAY, he was a top Canadian military commander who had flown planes for political figures and British royalty, including Queen Elizabeth II.

By night, however, David Russell Williams, 47, used the same logistical and organisational skills he acquired in the Canadian Air Force to break into homes, first stealing hundreds of pairs of underwear - many belonging to young girls - before progressing to raping some victims and then, finally, killing two of them.

The culmination of the case against Williams, which shocked Canadians when the colonel was first charged in April, came on Monday when he pleaded guilty to 88 charges, including rape, murder and a number of perverted home break-ins.

Gasps were intermixed with tears as a courtroom heard details of the scale and perversity of the crimes to which the military commander admitted on Monday.

Williams wrote detailed accounts of his crimes and meticulously photographed the evidence, compiling the data in what prosecutors called 'a deeply nested and complex series of sub-folders' on two computer hard drives.

He broke into houses primarily in the two neighbourhoods where he had homes. In many cases, he broke into the same house several times - in one instance, he did so nine times.

Dual life of sex predator