POUGHKEEPSIE, N.Y. — There was the night James Nichols introduced himself to his new neighbors on Vassar Road by walking in their front door without knocking. There was the afternoon Denise Darragh asked him to help her with an injured squirrel, and he — still wearing his suit jacket — killed it with a hatchet as the children playing in her yard screamed. And the day she was painting the house, wearing cutoff shorts, and turned around to see him taking photos of her from below with a long camera lens.

In later decades, after Mr. Nichols’s wife disappeared — she had killed herself or run away, he told relatives and friends and the police, though they had doubts — he withdrew from the neighbors as his little white house retreated from the world. On the collapsing roof, neat gray shingles gave way to drooping tar paper. In the garage, hills of junk grew higher. On the rare occasions Mr. Nichols appeared, he would be sitting in his car in the driveway, drowsing or reading the paper or maybe doing nothing at all.

When he was found dead in December, slumped in a chair inside his home in this Hudson Valley town, there was no will to be found, only masses of decaying books, cameras and computers. Six months later, a clean-out crew delving into the detritus found a hollow-sounding false wall in the basement.

Behind that wall, a barrel-shaped container. Inside the container, a black garbage bag bound with rope. Inside the bag, the skeletal remains of a woman missing nearly 30 years: JoAnn Nichols, his wife, disinterred on June 28 a floor below where she used to charm visitors with a honeyed Southern accent and a ready smile.