AUGUSTA (WGME) -- A teenager convicted of stabbing and killing her parents and their pet dog at the family's home in Winthrop in 2016 will be sentenced Tuesday.
Andrea Balcer stabbed her parents, Alice and Antonio Balcer, on Halloween morning in 2016.
Born a male, Balcer now identifies as a female and prefers to be called Andrea.
Minutes after killing her parents, prosecutors say Balcer called 911 and told a police dispatcher she just snapped.
Prosecutors say Balcer later confessed she planned to kill her parents.
Defense Attorney Walt McKee says Balcer thought her parents would not be supportive of her transition to become "Andrea Balcer" and that’s why she killed them.
Balcer also pleaded guilty to killing the family dog so it wouldn't bark while she killed her parents.
Balcer's older brother, who was spared that morning, says their parents were loving and supportive.
She pleaded guilty under an agreement that caps her sentence at a maximum of 55 years.
Balcer's sentencing is scheduled for 1 p.m. at the Capital Judicial Center in Augusta.