PORTLAND (AP) — A 33-year-old Maine man has denied allegations that he fatally shot his wife inside their Windham home in January while the couple’s three children were upstairs in their rooms.

The Portland Press Herald reported (http://bit.ly/1q09tIs ) Noah Gaston pleaded not guilty Tuesday to murder and manslaughter charges stemming from 34-year-old Alicia Gaston’s death on Jan. 14.

Prosecutors say Alicia Gaston was walking up the stairs of their home around 6 a.m. that day when Noah Gaston, at the top of the stairwell, fired a single round from a 12-gauge shotgun into her torso.

Noah Gaston has long contended that he mistakenly believed his wife was a home intruder.

Maine State Police charged Gaston with knowing and intentional murder, and a Cumberland County grand jury added the manslaughter charge when indicting him.