O’Keefe’s niece was just 14 years old when her uncle “JJ” died. She took the stand in Karen Read's murder retrial Wednesday.

John O'Keefe's niece was the first witness to take the stand at Karen Read's trial Wednesday morning.The niece, who WBZ-TV will not identify by name, is now a high school junior. She was around 14 years old when John O'Keefe died.

The forensic scientist will continue her testimony under cross-examination when the trial resumes at 9 a.m. Thursday. Read, 45, is charged with second-degree murder in the death of O’Keefe, who was found outside the home of a fellow Boston police officer on Jan. 29, 2022.