The former commander of Canada's largest air force base said Thursday he deeply regretted his "despicable crimes," moments before he was sentenced to life in prison for murdering two women.

Col. Russell Williams pleaded guilty to two counts of first-degree murder, two sexual assaults and 82 counts of breaking-and-entering, during which he took hundreds of undergarments from women and young girls.

Ontario judge Robert F. Scott sentenced Williams after the disgraced former elite pilot tearfully addressed the court, lamenting his crimes and the pain he has caused the victims and their family and friends.

"I stand before you indescribably ashamed," Williams said, his voice cracking. "I know that the crimes I have committed have damaged many people."

Williams said he betrayed his family, friends and colleagues.

Justice Robert Scott said he believes Williams is sincere in his regrets, but nonetheless declared him a "sick and dangerous" man. Williams would not be eligible for parole for 25 years.

"Russell Williams will forever be remembered as a sadosexual serial killer," Scott told the court. "The depths of the depravity shown by Russell Williams have no equal."

Williams pleaded guilty Monday to murdering Jessica Lloyd, 27, whose body was found in February, and Marie Comeau, a 37-year-old corporal under his command who was found dead in her home last November. Both women were asphyxiated.

Prosecutors spent much of the week revealing graphic evidence of the former elite military pilot's secret life at a sentencing hearing that often reduced the victims' family members to tears.

Williams took pictures of himself in the women's bedrooms, posing in their underwear, and he meticulously catalogued the photos on a hard drive and stored the undergarments in his home. Prosecutor David Thompson detailed in court how Williams raped, photographed, videotaped and killed Comeau, who pleaded with Williams to "have a heart" and spare her life. During most of the proceedings, Williams sat looking downward.

Williams was a rising star in the military before he was charged earlier this year. The charges have shocked Canadians and shaken the military to its core. The 47-year-old once flew prime ministers and served as a pilot to Queen Elizabeth II during a 2005 visit.

Canadian Prime Minister Stephen Harper called it a "horrific series of events" and said his thoughts are with the victims and to their families as well as to the Canadian military.

"Our thoughts go out to all the members of the Canadian forces who knew the commander and who have been very badly wounded and betrayed by all of this," Harper said.

Lieutenant-General Andre Deschamps, Chief of Air Staff for the Canadian military, said the military has been "deeply shaken" by Williams. Deschamps said they can now fire Williams and remove his medals.

"We don't understand why," Deschamps said. "This individual was a man of tremendous capacities. He was professional. I still can't reconcile the two people we've seen."

Jeff Farquhar, Williams' best friend since the two attended the University of Toronto together, said he's sickened, speechless and angry after seeing and hearing the "perverse and disgusting details" this week.

"I continue to toss in my mind years and years of conversation with Russ to see if I missed anything, but never is there a hint," Farquhar told the Associated Press.

Andy Lloyd, one of the victim's brothers, said he has been waiting for this day for a long time and that he's glad the military has moved to strip of Williams of his rank.

"My father served in the forces for 25 years and would never believe that a man of his stature could have done what monstrous things he did," said Lloyd outside the courthouse. "As long as he dies in jail, I'm happy."


Associated Press writer Rob Gillies contributed to this story from Regina, Saskatchewan.