The case dates back to 1986 when Curtis Lee Ervin was convicted in the murder-for-hire death of an associate's ex-wife.
Price says the prosecutor illegally excluded prospective jurors who were Black and Jewish.
The state attorney general agreed.
"Deputy District Attorney Mr. Anderson, during jury selection, he exercised his challenges in a way to exclude 9 of the 11 Black jurors and one Jewish juror," said Pamela Price, Alameda County District Attorney.
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DA Price says she will consult with the family of the victim before deciding to retry the case.
ABC7 News spoke to former Alameda County District Attorney Tom Orloff who was a high-ranking prosecutor in the office at the time.
"There was no policy in the office to discriminate against jury selection," he said.