The mother of a Manhattanville College student found slain in her school apartment today pled guilty to manslaughter charges. 

Stacey Pagli admitted that she killed her 18 year old daughter Marissa February 22, 2010 following an argument.

Pagli was originally charged with murder. In exchange for her guilty plea she will serve 20 years in prison. She had been examined by several psychiatrists following the shocking killing, most of whom agreed she was suffering from "emotional disturbance."

Pagli remains at the Westchester County Jail without bail.

Sentencing is set for April 5.