Richard Poplawski was found guilty Saturday of shooting and killing the officers responding to a domestic disturbance call at his mother's home in April 2009, the Pittsburgh Post-Gazette reported.
Poplawski was 22 at the time.
The victims' family members, police officers and medical responders are among 121 people who could potentially testify against Poplawski during the penalty phase of the trial in the Allegheny County Courthouse in Pittsburgh, the newspaper said.
The defense says it may call Poplawski's parents as character witnesses along with family friends, three doctors, two nuns and a priest.
Prosecutors are expected to cite aggravating circumstances in their pursuit of the death penalty, including the killing of more than one victim, killing an on-duty law enforcement officer and creating grave risk to other people.
If jurors vote to impose the death penalty, the defendant can appeal to the state Supreme Court and also challenge the sentence in federal court, a process that could go on for many years, legal experts said.