A top Canadian commander, who headed the country's biggest military base at Trenton till his arrest in February, has been exposed as a serial killer with a fetish for lingerie he kept as trophies.Col Russell Williams, 47, Monday pleaded guilty to raping and killing two women, sexually targeting teen girls and women in their 30s and indulging his fetish for lingerie by taking photographs of himself modelling in them and masturbating for the camera.So obsessed was he that he would break into homes to steal the lingerie to keep them as his trophies in his Ottawa home. He logged the stolen innerwear, with their date-stamped photos on hard drives recovered from the ceiling of his home.If the pile of the loot became too big, the commander would burn some to make room for more, the court heard.A rising military star who flew prime ministers and Queen Elizabeth II during her visit here, Williams was arrested Feb 4 at a roadside checkpoint in Ottawa just after Jessica Lloyd, 27, was killed.Police detained him after his SUV's unusual tires matched the tread marks left at the crime scene.A man in a stable marriage, Williams pleaded guilty to killing Jessica Lloyd, 27, in February and Corporal Marie Comeau, 38, his subordinate at the base, in November.He videotaped the asphyxiation death of Comeau after breaking into her home Nov 24, 2009. And he made tapes of his sex assault of Lyold after kidnapping her, taking her to his cottage, and raping and then killing her January 28.Apart from pleading guilty to killing two young women, including a subordinate, he admitted sexually assaulting two others as well as 82 counts of home break-ins to steal panties from women's bedrooms in Tweed - a small town northeast Toronto.Another 21-year-old single mother told the court she was tied up, blindfolded, stripped and held captive for more than two hours while he forced her into sexual acts and photographed her.The shocking double life of the once respected commander unfolded on court screens after his after his guilty plea Monday when the prosecution presented his pornographic images to show depths of his sexual perversion.The courtroom was stunned when it saw the commander wearing a 12-year-old girl's cartoon-decorated panties. The court heard that Williams knew the parents of the 12-year-old girl and visited the girl's bedroom two more times to take photos of himself.

Reacting to the guilty plea by his former top commander, Canadian armed forces chief Walt Natynczyk said, "The tragic events surrounding Col. Russell Williams stunned all Canadians and none more so than the members of the Canadian Forces. Today's guilty plea is the first step in a healing process that will no doubt take many years."