But the State Attorney's Office wouldn't take capital punishment off the table, listing seven "aggravating factors" that a jury can use to justify ordering Cruz's execution for the February 14 shooting rampage at Marjory Stoneman Douglas High School.
A plea deal is still a possibility for Cruz.
Another factor: "The capital felony was a homicide and was committed in a cold, calculated and premeditated manner without any pretense of moral or legal justification".
Cruz's attorney, Broward County Public Defender Howard Finkelstein, said in a statement to ABC News that the move by prosecutors "was not unexpected".
"We still stand ready to immediately plead guilty to all counts - to 34 consecutive life sentences without parole", Finkelstein said.
Cruz was arrested shortly after committing the Valentine's Day killings and fleeing the Marjory Stoneman Douglas High School campus among terrified students. Such a case would be among the state's highest-profile recent prosecutions, and it would also be a rarity following a mass shooting, which usually do not end with attackers taken into custody.