Authorities say they broke into an apartment to look for prescription drugs in 2005. Officer Daniel Enchautegui (en-chow-TAY'-gee) confronted them and was killed in a shootout. Armento is accused of firing the fatal shot.
Brancato, who played an aspiring mobster on HBO's "The Sopranos," says he didn't know Armento had a gun.
Brancato's murder trial is set for Oct. 28. Armento goes on trial Sept. 29.