Sellers made the same insanity claim to his clemency board, but the board refused to consider the issue.
The human rights group initiated a letter-writing campaign and delivered 4,000 letters to the clemency board.
The parole board would send its findings and recommendations to the clemency board, which would then hold a hearing on the case.
Ms. Warren, who has served more than half of her sentence, went before the clemency board this month but was denied clemency.
The clemency board, which consists of the governor and his three cabinet members, has files on each applicant.
"They paid no price, and the numbers are astounding," he says, reading from the uncontested documentation of the Ford Administration's clemency board.
"Usually some clemency board, or the governor or someone, will step in."
Convicted murderers, sexual predators and "violent career criminals" will still need an investigation of their case and a hearing before the clemency board.
The next meeting of the state's clemency board is scheduled for June 14.
The state attorney general recently suggested enlarging the overall staff and having the clemency board meet more frequently, but more substantial action is needed.