Moraine Valley College Student Charged in Mom's Stabbing Death

OAK LAWN, IL — A former St. Rita of Cascia High School student is accused of stabbing his mother to death during an argument early Saturday morning in Oak Lawn. William Sink, 19, is charged with first-degree murder in the slaying of his mother.

Sink is currently hospitalized at Advocate Christ Medical Center where he is receiving psychiatric treatment. An Oak Lawn police detective was in court Monday filing a “no-body warrant.” Cook County Judge Patrick Rogers set bail at $2 million.

The prosecutor said Sink and his 50-year-old mother, Grace Sink, were having an argument around 3 a.m. Saturday, Oct. 22, in the family’s home in the 4600 block of West 106th Place. Sink was separated from his mother and went outside with his younger brother and their mother’s boyfriend.

When they were outside, Sink began fighting with his younger brother and mother’s boyfriend, allegedly knocking the man unconscious. Sink went back into the house where his brother saw him on top of his mother hitting her, the prosecutor said.

The brother was able to get Sink off their mother, and his brother left the room. Around 4:45 a.m., the boyfriend was asleep in the bedroom, when he was awakened by the sound of arguing between Sink and his mother, according to the prosecutor.

The prosecutor stated the boyfriend saw Sink on top of his mother hitting her, unaware that she was being stabbed. The boyfriend pulled Sink off his mother. The boyfriend and Sink fought, both receiving injuries.

Grace Sink was able to get to a phone upstairs where she called 911 reporting that she had been stabbed. Grace was taken to Christ Medical Center where she went into surgery. The prosecutor said that she survived surgery but later died after going into cardiac arrest. She was pronounced dead at 9:27 a.m. Saturday.

William Sink was also taken to Christ Medical Center because he was uncontrollable at the time of his arrest, according to police.

Oak Lawn police, along with the South Suburban Major Crimes Task Force, conducted the investigation into the homicide. While at the home on Saturday, investigators learned that Grace Sink had passed away.

The Cook County State’s Attorney’s Office approved a first-degree murder charge against Sink on Sunday, Oct. 23.

The Oak Lawn detective told the judge Sink is in need of psychiatric care. The hospital staff recommended that he be transferred to Cermak Hospital.

Sink has no prior criminal background, the prosecutor said.

Sink’s attorney said he is a graduate of St. Rita and currently enrolled at Moraine Valley Community College. His father, a Chicago police officer, was in court. The attorney said the family could probably post an $8,000 bond with electronic home monitoring.

A photo on St. Rita’s website shows Sink as a member of the high school’s varsity hockey team during the 2015-2016.

Sink is due back in court Nov. 17 in Bridgeview.

Photo: William Sink, 19, of the 4600 block of West 106th Place, Oak Lawn | Oak Lawn Police Department

This story has been updated with new information.