Lawyers for the former 1960s radical, sought a new trial for the Muslim cleric on grounds prosecutors violated Al-Amin's right not to testify for himself, the Atlanta Journal-Constitution said.
He was convicted of malice murder, felony murder, aggravated assault on a peace officer and other charges.
Ricky Kinchen and another sheriff's deputy went to Al-Amin's home March 16, 2000, to serve him with missing a court date on charges of receiving stolen property and impersonating a police officer.
Investigators said Al-Amin opened fire with an assault rifle, killing Kinchen and wounding the other deputy. Al-Amin was captured four days later in Alabama.
During closing arguments in the trial, the prosecution mentioned the defense's decision against calling Al-Amin.
"We find that the error, although of a constitutional magnitude, was harmless beyond a reasonable doubt," the court ruled.