Armento, 50, allegedly shot Enchautegui while he and Brancato, 31, allegedly were attempting to burglarize the off-duty officer's home in 2005. Armento was charged with first-degree murder, while Brancato was charged with second-degree murder.
The New York Post said Dr. Ajay Chopra told a Bronx judge Monday Armento hadn't had any pain medication stronger than Tylenol for 24 hours before he made a written statement to police, confessing to shooting Enchautegui.
Medical records show Armento was "alert and oriented" when he stated he had outgunned Enchautegui, the Post said.
Brancato is best known for his roles in TV's "The Sopranos" and the film "A Bronx Tale," starring Chazz Palminteri.