Wilson told the AP Wednesday that prosecutors had not responded to the offer and said he didn't know whether prosecutors had relayed the offer to any victims as required by state law.
Prosecutors said that violated the gag order.
They also said they have repeatedly contacted "every known victim and family member of a victim — numbering over one thousand" about possible resolutions of the case, including the death penalty and life in prison without parole.
George Brauchler, the Arapahoe County district attorney, is scheduled to announce Monday whether he will seek the death penalty for Holmes. Brauchler hasn't publicly revealed his plans. He has refused repeatedly to comment on the case, citing the gag order.
Pierce O'Farrill, who was shot three times, said he would welcome an agreement that would imprison Holmes for life. The years of court struggles ahead would likely be an emotional ordeal for victims, he said.
"I don't see his death bringing me peace," O'Farrill said. "To me, my prayer for him was that he would spend the rest of his life in prison and hopefully, in all those years he has left, he could find God and ask for forgiveness himself."
A plea bargain would bring finality to the case fairly early so victims and their families can avoid the prolonged trauma of not knowing what will happen, said Dan Recht, a past president of the Colorado Criminal Defense Bar.
"The defense, by making this public pleading, is reaching out to the victims' families," he said.
Associated Press writer Nicholas Riccardi contributed to this report.