Holding: Consent to search is question of constitutional (as opposed to historical) fact, and therefore subject to independent review on appeal. Defendant consented to warrantless search of bedroom: agents went to house to investigate drug transaction; one asked deft. If they could enter bedroom and collect the drugs, & deft. opened door & walked inside. Agents followed him, assuming from this conduct that they permission to enter. Deft. retrieved drugs & handed them to agent. Court stresses absence of trickery or coercion in sustaining entry & search.