What is the test for reasonable inference or strong suspicion of possession of marijuana seeds?

We quoted the foregoing language with approval in an unlawful search case, stating that, "it seems clear that the mere presence of two burnt marijuana seeds would not give rise to a reasonable inference or strong suspicion that the occupants of the apartment in which the seeds were found were presently guilty of a crime. It is now well established that evidence of useless traces or residue of narcotic substances do not constitute sufficient evidence to sustain a conviction for possession of narcotics. [Citations.] Although the presence of two burnt marijuana seeds might reasonably suggest that defendant or another occupant of the apartment formerly possessed and used marijuana, that inference would not justify their arrest for present use, possession or sale." (People v. Fein (1971) 4 Cal.3d 747, 754, 94 Cal.Rptr. 607, 484 P.2d 583, italics added.)