TROY, N.Y. — A 23-year-old man has pleaded guilty to arson and manslaughter for an upstate New York apartment fire that led to the death of an 82-year-old woman.

The Rensselaer County District Attorney’s office says David Stanley is the last of three suspects to plead guilty for the May 2015 fire that destroyed an apartment building in Troy. Tyler Smith of Castleton pleaded guilty to arson and manslaughter in July, and 21-year-old Abby Slaga pleaded guilty to reckless endangerment.

Grace Halpin died at a hospital a month after she suffered a heart attack during the early-morning blaze.

Investigators say gasoline was used to set the fire. A video showed three people running from the burning building.