A 20-year-old mother was arraigned Friday afternoon on manslaughter charges for allegedly shaking her 1-year-old daughter to death last week at Century Country Club in Purchase.

Police say Anthonica St. Victor, of Yonkers, shook her daughter Carissa so violently that the girl suffered a brain injury. St. Victor was visiting her boyfriend, who worked at the country club, last weekend when the incident occurred. The child later died after being taken off life support.

Investigators claim there was enough physical evidence in the boyfriend?s room to establish that the baby was shaken so violently that is what led to her death.

According to officials, the case was especially difficult to investigate due to the nature of the abuse. The child suffered 23 broken ribs and blunt force trauma. They also say they?ve never seen a mother so cold and unremorseful about the death of her baby daughter, who just turned one two weeks ago.

?This was a crime that broke the hearts of all the investigators,? says Police Chief David Hall.

St. Victor?s boyfriend, who is not the child?s father, is not being charged. He was, however, fired from the country club. Cops say the mother?an illegal immigrant form Haiti who lives in Yonkers--is showing no regret for what she did. Police believe she was the sole perpetrator in the crime.

St. Victor is currently being held without bail at Westchester County jail.