In an interview with Grantland, Deputy Jones acknowledged confronting Mr. Hillary but denied threatening him, saying he was just trying to “have him man up.”

“I go, ‘Listen. Help me understand. Are you and Tandy together?’” Deputy Jones said.

Ms. Cyrus, 37, declined to be interviewed for this article, but Mr. Hillary said he had been harassed because of his relationship with her. “It’s not a community with a lot of interracial relationships,” he said, adding that he had “to be mindful” when he was out. “I would go to the local restaurant,” he said, and Deputy Jones’s “friends would come up to me and like, ‘You know you’re not supposed to be dating John’s girl.’”

A few months after they met, Mr. Hillary and Ms. Cyrus moved in together, forming a household of five, including his teenage daughter, Shanna-Kay, and Ms. Cyrus’s two sons.

The couple had different approaches to parenting, with Ms. Cyrus telling the police that Mr. Hillary was controlling and judgmental.

“Nick would sit me down almost on a weekly basis, and he would tell me everything that was wrong with my kids,” Ms. Cyrus said in the draft deposition she gave to the police, adding that Mr. Hillary had an undue need for structure and planning. And, she said, her children — particularly Garrett — “did not like Nick.”

Patricia Phillips, Garrett’s grandmother, shared this view. “My grandson would be here at night and get ready to have to go back down there and cry because he didn’t want to go home,” she said, sitting in her home in Parishville, surrounded by smiling pictures and portraits of Garrett and her son Robert.

Mr. Hillary insisted that he and Garrett got along: He said he helped Garrett with homework and had attended his basketball games, treating the boy the same way he treated his own son, Lashaka-mani, who was two years younger.