A tire track in the snow brought detectives to the country home of Colonel Russell Williams, the commander of 8 Wing/CFB Trenton, one of the biggest military bases in Canada.
That was the beginning.
Perched on the edge of ice-encrusted Lake Stoco, a short drive outside this placid town north of Belleville, the sprawling bungalow Col. Williams, 46, owns with his wife, Mary Elizabeth Harriman, would look like any other rural property were it not for the yellow police tape and the forensics truck.
In sleepy Tweed, a community that includes many retired people, farmers and people who commute to Belleville, the mounting alarm that followed a pair of disturbing assaults last September and peaked with the disappearance of Jessica Lloyd in late January is slowly subsiding.
There was quiet panic in the community when rumours began to circulate about the nature of the two sex assaults in September of a woman in her 40s and another about 20 years younger.
Both victims lived alone, and both attacks occurred in the dead of night.
An intruder bound both women with duct tape and blindfolded them with pillow cases. Naked, they were tied to chairs and photographed.
The attacker took elaborate precautions. In each case, a source said, he laid bed sheets on the floor, or possibly blankets, and positioned the women and the chairs on the sheets.
When he was done, he took the sheets away with him, clearing the crime scenes of possible evidence, such as DNA traces.
The blindfolds - neither woman glimpsed their attacker's face - were crucial.
"It's best you don't recognize me," he told one. And he even evinced a hint of courtesy, at one point going to a bathroom cabinet to fetch her some aspirin.
The fears of area residents were heightened by the asphyxiation death in November of 38-year-old Corporal Marie-France Comeau, found slain in her home in Brighton, about 20 kilometres west of the Trenton air base. Like the two sexual-assault victims, Cpl. Comeau had been bound with duct tape.
Then, on Jan. 29, Jessica Lloyd, a 27-year-old Belleville woman, vanished without explanation, leaving both her cellphone and wallet in her home.
Amid police warnings that a predator might be on the loose, a massive investigation was launched.
The break in the case came last Thursday, as police canvassed the residents of Highway 37, which connects Tweed and Belleville.
Back at Ms. Lloyd's home, the impression of a distinctive tire track had already been lifted from the snow. Col. Russell was driving toward Tweed when he was stopped by police at a rolling road block. An officer noticed the tires on his car and began asking questions.
"Something about him wasn't right, he was more evasive than he needed to be," a source familiar with the investigation said.
So the colonel was asked to come in for questioning.
Col. Williams then allegedly took police to Ms. Lloyd's body, hidden in woods along Cary Road, near Tweed.
Editor's note: An earlier version of this story mistakenly referred to Col. Williams as Col. Russell.