In Florida v. Riley, a police investigator, acting on information from an informant, flew a helicopter over respondent Riley's dwelling and greenhouse at 400 feet to determine whether marijuana was being grown in the greenhouse. With his naked eye, the investigator looked through openings in the greenhouse roof from the helicopter and saw what he thought was marijuana growing inside the greenhouse. He then obtained a search warrant based on his observations. A search revealed marijuana growing in the greenhouse. Riley was charged under Florida law with marijuana possession. The trial court granted Riley's motion to suppress the evidence of the search on the ground that the helicopter search was undertaken in violation of the fourth amendment. The Florida Court of Appeals reversed the trial court but certified the case to the Florida Supreme Court. The Florida Supreme Court reinstated the trial court's order to suppress. The U.S. Supreme Court held that the helicopter search did not violate the Fourth amendment prohibition against illegal searches and seizures.