Col. Williams told his interrogator that he bound Ms. Lloyd's body and stored it in his garage. Three days later, after flying troops to California, he dumped it in a rural area.
He said he killed Ms. Lloyd because she knew he was taking pictures and the police would connect the photos to his two previous sexual assaults in Tweed. Asked what he thought while he was attacking Ms. Lloyd, he said she was "a very nice girl."
Col. Williams also described how he broke into Cpl. Comeau's house and hid in the basement, where she found him while looking for one of her cats. He said she didn't recognize him because his face was disguised, but yelled "You bastard!" when she saw him.
Cpl. Comeau tried to fight him off but Col. Williams tied her up, gagged her and viciously beat and sexually assaulted her. She passed out at one point from his blows and he had to carry her upstairs.
He says he strangled her, and then corrects himself, "Well, I suffocated her." Asked why, he replied: "Again, because of the pictures. There was going to be a straight line back to Tweed."
As he recounted what he did to Cpl. Comeau, answering every question, Col. Williams's tone was subdued and yet strikingly casual. He also admitted to the two sexual assaults.
He said he chose the corporal because she had mentioned that she lived alone. He checked her schedule and timed his first visit to her home, in which he stole some lingerie, for when she was out of town.
At one point, Col. Williams was asked why he thinks these things happened. His response: "I don't know." And then: "I'm pretty sure the answers don't matter."
He later said he feels "disappointed" at his actions. He was asked whether he would have continued such crimes and said, "I was hoping not" before adding that he can't answer the question.
Also Wednesday, the court released often chilling letters Col. Williams wrote to his wife and victims during a break in the interrogation.
To his wife, Mary Elizabeth Harriman, he wrote: "Dearest Mary Elizabeth, I love you, Sweet [illegible] I am so very sorry for having hurt you like this. I know you'll take good care of sweet Rosie [their cat] I love you, Russ".
He wrote the following to Ms. Lloyd's mother: "Mrs. Lloyd, You won't believe me, I know, but I am sorry for having taken your daughter from you. Jessica was a beautiful, gentle young woman, as you know. I know she loved you very much - she told me so again and again. I can tell you that she did not suspect that the end was coming - Jessica was happy because she believed she was going home. I know you have already had a lot of pain in your life. I am sorry to have caused you more."
To Ernest Comeau, the father of Cpl. Comeau, he wrote: "I am sorry for having taken your daughter, Marie-France, from you. … I know you won't be able to believe me, but it is true. Marie-France has been deeply missed by all that knew her." (Shortly after her death, Col. Williams wrote Mr. Comeau an official condolence letter, making no mention of his role in her murder.)
To his first sex assault victim, who can't be named, he wrote: "I apologise for having traumatized you the way I did. No doubt you're left a bit safer now that I've been caught."
And to Laurie Massicotte, the second woman he sexually assaulted, he also apologized. "Laurie, I am sorry for having hurt you the way I did. I really hope that the [illegible]we had has helped you turn your life around a bit. You seem like a bright woman, who could do much better for herself. I do hope you find a way to succeed." (Ms. Massicotte waived the right to have her identity shielded by the court.)
Editor's Note: An earlier version of this online story contained an incorrect word in the transcription of Col. Williams's letter to victim Jessica Lloyd's mother. This version has been updated.