TORONTO, Canada (AP) — Canadian authorities are looking into unsolved murder and sexual assault cases after charging the commander of Canada’s largest Air Force base with the murder of two women and the sexual assault of two others.

Col Russell Williams was arrested Sunday and charged with the murder of two women, including a soldier who was under his command. Williams was once an elite pilot who flew prime ministers.

News of the charges rocked the military.

Ontario Provincial Police Sgt Kristine Rae said the core of the investigation is still geared toward the four cases. However, she said investigators are looking at other areas where he has been posted and other crimes that have gone unsolved to see if there are any similarities.

Williams, 46, is a career military man who has been stationed across Canada and internationally. The four crimes he is charged with took place between September and February.

Williams was appointed as the base commander of Canadian Forces Base Trenton in Trenton, Ontario last July. Trenton is Canada’s busiest Air Force base and is providing logistical support for Canada’s missions in Afghanistan and Haiti. It is Canada’s most high profile base as the bodies of all soldiers killed in Afghanistan are flown there.

Williams welcomed the Olympic torch there earlier this year.

Police have told the mother of Kathleen MacVicar, 19, of Glace Bay, Nova Scotia, they are re-examining her case in connection with Williams. MacVicar was staying with relatives at Trenton when she was sexually assaulted and fatally stabbed at the base in 2001.

“I’m pleased that they’re looking at it again, I am,” Colleen MacVicar said with a heavy sigh.

“It would be nice if it was solved, but I’m just waiting here. I’m not getting my hopes up. We’ve been disappointed before.”

Williams is charged with the first-degree murder of Jessica Lloyd, 27, a Belleville, Ontario, resident whose body was found Monday, and Marie Comeau, a 38-year-old corporal found dead in her Brighton, Ontario, home in November.

Authorities said Williams came to the attention of police during a roadside canvas on February 4, six days after Lloyd was deemed missing.

Williams is also charged with forcible confinement, breaking and entering and sexual assault after two women were sexually assaulted during two separate home invasions in the Tweed, Ontario area last September

Williams was photographed last month with Defence Minister Peter MacKay and Canada’s top general during an inspection of a Canadian aircraft that was on its way to support relief efforts in Haiti.

Major General Yvan Blondin, the direct commander of Williams, said Williams was considered a “shining bright star”.

Between December 2005 and June 2006, Williams was the commanding officer for Camp Mirage, the secretive Canadian Forces forward logistics base that is not officially acknowledged by the government or military but has been widely reported to be near Dubai.

Mark Safarik, who spent more than 12 years as a senior profiler in the FBI’s Behavioural Analysis Unit, said it’s unusual to see someone Williams’ age arrested for sensational crimes with no prior record.

Police looking at unsolved cases after the charges against Williams will examine homicides and sex crimes but also precursor-type crimes such as burglaries, said Safarik, who is now retired.

“There’s typically an escalation of behaviour that has occurred over a long period of time, and it’s this precursor types of crimes that they’ll be looking for,” he said.

Safarik said as an investigator he would focus on burglary cases.

“Burglary cases at night where nothing is taken where victims are saying things like, ‘I felt like there was somebody in the house but I didn’t find anything missing, I heard somebody, I thought I saw somebody at my window, prowling, peeping,”‘ he said.

Police left Williams’ Ottawa home with bags yesterday and were also combing his cottage in Tweed, Ontario for evidence.

“Shocked is an understatement,” said neighbour Michael Gennis of his reaction to Williams’ arrest.

Williams is scheduled to appear in court by video on February 18.

Williams’ wife, Mary-Elizabeth Harriman, has taken a leave of absence from her job as the associate executive director of the Heart and Stroke Foundation of Canada.