How is a postarrest statement to police admissible?

Prior to trial, and without objection on Miranda grounds, the court ruled admissible defendant's postarrest statement to police after being read his Miranda rights. (See Miranda v. Arizona (1966) 384 U.S. 436, 86 S.Ct. 1602, 16 L.Ed.2d 694.) After one of the officers indicated that he wanted to talk about the Riverside County murder, defendant asked, "What do you want me to say?" The officer replied that he only "wanted to talk about the truth." Whereupon defendant stated, "If I could only cry, but I can't cry. I couldn't even cry when my mother died." No further conversation took place.