A federal judge on Wednesday ordered Lee Baca, a former Los Angeles County sheriff convicted of obstructing an F.B.I. investigation into his department’s troubled jails, to report to prison within three weeks.

Mr. Baca, 77, was convicted in March 2017 on felony counts of conspiracy to obstruct justice, obstruction of justice and lying to federal investigators. He was sentenced that May to three years in prison, but he remained free on bond throughout his appeal, according to court documents.

The United States Attorney’s Office for the Central District of California, which prosecuted the case, declined to comment on Thursday. Lawyers for Mr. Baca did not immediately return phone calls or respond to emails seeking comment on Thursday evening.

On Monday, the Supreme Court denied a petition to open his case for review, clearing the way for Judge Percy Anderson of United States District Court to set the deadline for Mr. Baca’s surrender.