New details about Col. Russell Williams' self-admitted secret life are expected to emerge on Monday after the former military commander delivers his expected guilty pleas in the murder of two women.

Williams, who once commanded CFB Trenton, is also set to enter guilty pleas in a pair of sex assaults and dozens of break-ins when he appears before an Ontario judge on Monday.

While the charges against Williams have made headlines across the country, it has thus far been difficult to match the credentials of a well-known military man with the lurid and brutal sex-related allegations that emerged after his arrest in February.

"This is the type of case that we simply haven't seen in Canada before," said Toronto criminal lawyer Adam Boni in an interview with The Canadian Press.

"I say that because this gentleman (according to his own admission) lived such an incredible double life, it's almost a 'Jekyll and Hyde' type of case. It's the deepest, darkest fear that each and every one of us has about the neighbour down the street, or the teacher at school, or the seemingly normal business professional walking down the street."

Williams' ascent within the military was abruptly halted when he was charged with first-degree murder in the deaths of Jessica Lloyd, 27, and 38-year-old Cpl. Marie-France Comeau.

Along with the killings and two sex assaults, Williams' lawyer told an Ontario court earlier this month that his client would also plead guilty to 82 counts of break-and-enter.

Though the sheer number of break-ins is shocking in itself, equally disturbing are allegations that the break-ins involved stealing lingerie from women's homes.

"The allegations in this case would appear to be so lurid, so disturbing that a trial in this case would probably have changed the Trenton community for the rest of its existence," Boni said.

"It would have had a thunderous impact on the local community and it would have had a devastating impact on the victims and their families."

Though guilty pleas are expected on Monday, hearings to wrap up the case could last several days, as sentencing will follow. Ahead of sentencing, victim impact statements will be read in open court.

Still, it's unclear which evidence will be entered into the court record. According to reports, police have hours of video statements from Williams, 47, in which he allegedly details the crimes.

Even more troubling, however, is video footage which Williams allegedly shot himself. That evidence has not been entered into the court record.

Last November, Cpl. Comeau was found dead in her home in Brighton, Ont. She had been a flight attendant who served dignitaries onboard military flights in the 1990s -- some of which were piloted by Williams.

Ten days prior to the grisly discovery of Comeau, prosecutors allege that Williams broke into her home.

Last January, the disappearance of Jessica Lloyd sparked media publicity as police searched for any clues into the case. Her body was found in February on a small road in eastern Ontario. Lloyd had worked in nearby Napanee as a bus schedule co-ordinator.

Meanwhile, a woman who alleges that she was sexually assaulted by Williams has launched a civil suit against him. Court documents allege that the woman was left suicidal and fearful because of the "horrific and reprehensible" attack.

With files from CTV's John Vennavally-Rao and The Canadian Press