The United States (“government”) appeals from an order entered February 18, 1986 in the District of Minnesota, Robert G. Renner, District Judge, granting the motion of Raymond and Eileen Martin (“ap-pellees”) to suppress certain contraband seized from the front seat of their pick-up truck. The court held that, because no exception to the warrant requirement of the Fourth Amendment was applicable to the seizure of machine gun parts pursuant to a warrantless search of appellees’ truck, the seizure was unreasonable within the meaning of the Fourth Amendment.
On appeal, the government argues that, under either the “plain view doctrine” or the automobile exception to the warrant requirement, the warrantless seizure was constitutionally permissible. We hold that a warrant was not required to seize the machine gun parts observed in plain view through the window of the truck parked on a public street.
We reverse.
I.
We summarize only those facts believed necessary to an understanding of the issues raised on appeal.
On April 12, 1985 agents of the Bureau of Alcohol, Tobacco and Firearms executed a search warrant at a house owned by appellees. The warrant was issued upon probable cause to believe that machine gun and silencer parts were being delivered to appellees’ house and that appellee Raymond Martin was engaged in an ongoing unlicensed gun business. The warrant authorized the agents to search the house for a machine gun, a silencer and silencer parts, among other things.
Immediately prior to executing the warrant, while surveilling the house, the agents observed Raymond Martin arrive in a pick-up truck. Martin parked the truck on the public street adjacent to his house which he then entered. The agents served Martin with a copy of the warrant and commenced the search. Appellee Eileen Martin was not present.
Several hours later one of the agents walked outside of the house into the yard. While standing on the curb along side the public street on which the truck was parked the agent looked through the passenger window of the truck. On the front seat the agent saw a clear plastic bag containing gun parts which he immediately recognized, as a result of his extensive training, to be the receiver of a Mach-Ten type weapon and a receiver of a British Sten machine gun. Diagrams used to construct a machine gun, already found inside the house, called for the type of receiver the agent saw inside the truck. After conferring with his supervisor, the agent opened the unlocked truck door and seized the bag containing the gun parts.
Appellees were indicted by a grand jury and charged, in violation of 26 U.S.C. §§ 5861(d) and 5871 (1982), with possessing machine guns not registered to them in the National Firearms Registration and Transfer Record. The indictment was based in part on the evidence seized from the house and truck. Appellees moved to suppress all evidence seized. A hearing was held before United States Magistrate J. Earl Cudd on January 3, 1986. On February 6, 1986 the magistrate filed a report recommending that the motions to suppress be denied in all respects. Appellees objected to the report and recommendation. A de novo review was conducted by the district court. In an opinion dated February 18, 1986 the district court accepted that portion of the magistrate’s report which recommended denial of the motion to suppress evidence seized from appellees’ house. The court, however, rejected that portion of the magistrate’s report which recommended denial of the motion to suppress evidence seized from appellees’ truck. Accordingly, the court ordered the evidence of the gun parts seized from the truck without a warrant suppressed, holding that the government could not justify the warrantless seizure under the plain view doctrine or the automobile exception or any other warrant exception. On February 24, 1986 the *206 government filed a motion for reconsideration of the order suppressing the evidence seized from the truck. The court denied the motion for reconsideration on February 28, 1986. On March 25, 1986 the government took the instant appeal pursuant to 18 U.S.C. § 3731 (1982).
For the reasons stated below, we reverse the order of the district court suppressing the evidence seized from appellees’ truck.
II.
The Fourth Amendment secures the persons, houses, papers and effects of the people against unreasonable searches and seizures by the government, and requires a showing of probable cause prior to the issuance of a warrant. Although the warrant procedure is the preferred method by which law enforcement agents conduct searches and seizures, courts have recognized that the overriding principle of the Fourth Amendment is one of reasonableness. Thus, exceptions to the warrant requirement have been carved out in a logical and flexible manner.
E.g., United States v. Ross,
A.
As for the observation of the gun parts in plain view on the front seat of the truck, we hold that the agent’s conduct was not a search within the meaning of the Fourth Amendment. The agent was standing on the curb abutting a public street. Appellees’ truck was parked on that public street. The agent testified that he could see clearly through the windows and that they were not covered in any way.
As stated in
Texas v. Brown,
“The general public could peer into the interior of [defendant’s vehicle] from any number of angles; there is no reason [the officer] should be precluded from observing as an officer what would be entirely visible to him as a private citizen. There is no legitimate expectation of privacy, Katz v. United States,389 U.S. 347 , 361 (1967) (Harlan, J., concurring); Smith v. Maryland,442 U.S. 735 , 739-745 (1979), shielding that portion of the interior of an automobile which may be viewed from outside the vehicle by either inquisitive passersby or diligent police officers. In short, the conduct that enabled [the officer] to observe the interior of [defendant’s vehicle], was not a search within the meaning of the Fourth Amendment.”
Id. at 740 (plurality opinion).
Our concern therefore is with plain view in the sense of there being no
search
within the meaning of the Fourth Amendment. In contradistinction is the “plain view doctrine” of
Coolidge v. New Hampshire,
Our conclusion that the plain view observation was not a search within the meaning of the Fourth Amendment settles only the constitutionality of the observation itself. Our inquiry does not end here. Rather, we turn next to the warrantless seizure of the gun parts to determine whether it passes constitutional muster.
B.
As for the opening of the truck door and the seizure of the gun parts, we hold that such conduct clearly was a seizure within the meaning of the Fourth Amendment. Our task now is to assess the reasonableness of such a warrantless seizure.
Here, the district court considered and rejected the automobile exception as a justification for the warrantless seizure because “there was no immediate threat that the truck’s contents would disappear.” We hold that the court erred in its application of the automobile exception to the facts of this case.
The automobile exception to the warrant requirement is well settled law.
E.g., Carroll v. United States,
These reduced expectations of privacy in the truck, however, are tempered by requiring the overriding standard of probable cause still to be met prior to a warrantless search and seizure.
Carroll, supra,
The seizure of the gun parts here was not unreasonable since the seizure was grounded in circumstances which would justify a magistrate in issuing a warrant to search the truck and seize the gun parts from the front seal. This is so regardless of the fact that such a warrant was not actually obtained.
United States v. Ross, supra,
We hold, therefore, that the agent’s war-rantless seizure of the gun parts based on probable cause was within the automobile exception to the warrant requirement and permissible under the Fourth Amendment.
III.
To summarize:
We reverse the order of the district court suppressing the evidence seized from ap-pellees’ truck. We hold that the conduct which permitted the agent to observe gun parts, in plain view, on the front seat of appellees’ truck was not a search under the Fourth Amendment. We also hold that the warrantless seizure of the gun parts, while implicating Fourth Amendment rights, was based on probable cause. The agent’s conduct was therefore constitutionally permissible within the automobile exception to the warrant requirement.
Reversed.
