A Tupper Lake woman has pleaded guilty to second-degree murder according to the Franklin County District Attorney’s Office, in relation to a July 2022 homicide. WTEN reports Alexa Gallagher, 26, intentionally caused the death of her mother, Melissa Guisewhite, by stabbing her with a knife. At the time of her death, Guisewhite was 51. Sentencing for Gallagher is scheduled for May 30 at 9:15 a.m.