DALLAS (AP) — Police in Texas are seeking a motive in the slaying of a witness who testified in the murder trial of a white Dallas police officer who fatally shot her black neighbor.

An attorney for 28-year-old Joshua Brown says he was shot to death Friday night. Lee Merritt says he spoke with Brown’s mother and she’s “devastated.” He says in a statement: “We need answers.”

Dallas police confirmed a fatal shooting Friday night, but have not said who was killed. The Dallas Morning News first reported that the person was Brown.

Brown lived in the same apartment complex as former Officer Amber Guyger. She was convicted of murder this past week in the death of neighbor Botham Jean. Guyger has said she mistook Jean’s apartment for her own and that she thought he was a burglar.