Attorneys for Jerry Amaro's family said on Wednesday they are asking the US Attorney's office to open a grand jury investigation into what happened.
Amaro was beaten in March 2000 during an arrest on suspicion for trying to buy drugs.
Amaro died a few weeks later from fractured ribs that led to pneumonia.
Tuesday evening, the city approved a $1.7 million settlement for Amaro's mother.
Neither the city nor the Oakland Police Department wanted to comment.