An Atlanta boy who stabbed his 76-year-old grandmother more than 50 times and went to school in blood-soaked clothes was sentenced Wednesday to 20 years in prison plus five years probation.

According to Channel 2 Action News, a judge sentenced 16-year-old Charles Price III after the teen pleaded guilty to manslaughter.

Price was 14 years old when stabbed his grandmother April 18, 2014, and went to Therrell High School, still covered in blood.

When teachers questioned Price, he allegedly said, “I killed it.”

Investigators went to the southwest Atlanta home where Price lived with his grandmother, they found Mary Price’s body inside and a gruesome scene, The Atlanta Journal-Constitution previously reported.

Prosecutors said Price, the mother of an Atlanta police officer, was upset with him because he had missed the school bus. The police officer is not the father of Price, police previously said.

Price was originally charged with murder. After doctors determined he had been suicidal at the time and suffered from severe depression anxiety, the charges were reduced to voluntary manslaughter, according to Channel 2.

Price said he has no memory of the stabbing.