Is possession of a large quantity of heroin sufficient to support the inference of knowing possession?

In United States v. Mora, 876 F.2d 76 (9th Cir.1989), we said that "[p]ossession of a large quantity of narcotics alone may be sufficient to support a finding that one knowingly possessed the heroin." Id. at 77-78. However, in that case, as in others where similar statements were made, there was other evidence to support the inference of knowing possession. Those cases considered the way the drugs were packed, nervousness at the inspection point, or failure of other people to meet the defendant as he had said they would. See, e.g., United States v. Barbosa, 906 F.2d 1366, 1368 (9th Cir.), cert. denied, 498 U.S. 961 (1990) (noting the ample additional evidence from which a jury could have inferred knowledge). None of those particular elements was present here.