The district court erred in allowing comment on appellant’s post-arrest, pre-Miranda (Miranda v. Arizona (1966) 384 U.S. 436) silence, even though he subsequently waived his right to remain silent and gave a statement to customs agents. The error, however, was harmless. Because appellant made inconsistent statements, and solely possessed a substantial amount of marijuana , the Court of Appeals concluded beyond a reasonable doubt that a jury would have convicted appellant without the comments upon his post-arrest, pre-Miranda silence. In contrast, the admission into evidence of appellant’s demeanor at the time he was accused of marijuana importation did not violate the Fifth Amendment. Although a gesture, such as a nod of the head, can be testimonial, this evidence of demeanor was not.