A commander who was a rising star in Canada's military pleaded guilty Monday to the murders of two women, the sexual assaults of two others and dozens of breaking and entering charges in which he stole panties from the bedrooms of girls as young as 11.

Col. Russell Williams, who once flew prime ministers and served as a pilot to Queen Elizabeth II during a 2005 visit, was the commander of Canada's largest Air Force base until he was charged earlier this year.

He pleaded guilty Monday to two first-degree murder charges, two sexual assaults and 82 breaking and entering charges in a Belleville, Ontario court. The 47-year-old faces an automatic sentence of life in prison with no possibility for parole for at least 25 years.

Williams was expressionless and dressed in a somber dark suit, and he kept his head down as the charges were read. The list of charges was so long that it took nearly 40 minutes to read it into the record.

"Guilty, your honor," he said after the charges were entered.

Prosecutors said Williams targeted girls and women in their teens and 20s and often photographed himself in their underwear.

At the sentencing hearing following his guilty plea, prosecutors warned the court they would be presenting evidence that was "extremely disturbing." Prosecutor Lee Burgess said much of the facts will be difficult for his victims to hear, but said it was "important to have a full account of the crimes."

Burgess began presenting photos showing Williams wearing a 12-year-old girl's cartoon-decorated underwear. Other photos showed him wearing underwear belonging to 11-year-old twins.

Many of the photos showed Williams masturbating in the stolen lingerie, either wearing it or with it draped over himself. People in the courtroom, many of them victims and their families, were in tears and appeared stunned. Roxanne Lloyd, the mother of murder victim Jessica Lloyd, clutched a frame photo of her daughter, wiping away tears as the prosecution relayed details of Williams' fetish behavior.

In another photo, Williams appears to be wearing his military uniform with his trousers dropped to show he is wearing pink panties. Burgess also presented evidence of Williams photographing himself naked with one of his victim's sex toys.

In each photo, he looks serious, with little expression. As prosecutors presented the evidence, Williams was again void of expression, his eyes cast downward the entire time.

Authorities said Williams carefully catalogued the photos of himself in the victims' underwear with time and date stamps on hard drives in his Ottawa home. Some of the photos were panoramic shots of the victims' bedrooms. He would take the lingerie with him, keeping them in bags and boxes in his home and would sometimes burn them if he ran out of space.

Prosecutors also said Williams videotaped the assaults and murders.

Williams, who was born in England and raised in Canada, had a promising future with the military. The square-jawed officer was pictured with the British queen and her husband, Prince Philip, on the front page of the newspaper of Canadian Forces Base Trenton during their visit five years ago. He was photographed in January with Defense Minister Peter MacKay and Canada's top general during an inspection of a Canadian aircraft on its way to support relief efforts in Haiti.

He is alleged to have killed his second victim just over a week after he appeared with MacKay.

Williams pleaded guilty to the murder of Jessica Lloyd, 27, whose body was found in February, and Marie Comeau, a 38-year-old corporal under his command who was found dead in her home last November. Both women were asphyxiated.

Williams also pleaded guilty to forcible confinement, breaking and entering and sexual assault after two other women were attacked during separate home invasions in the Tweed, Ontario area in September 2009.

Williams, a 23-year military veteran, has never been in combat but has been stationed across Canada and internationally, including a stint in 2006 as the commanding officer for Camp Mirage, the secretive Canadian Forces base widely reported to be near Dubai. Investigators looked into other areas where he has been posted.

Williams' wife, Mary-Elizabeth Harriman, works as the associate executive director at the Heart and Stroke Foundation in Ottawa.