OPINION
Defendant Dayton Belgard appeals his conviction by bench trial for possession of a dangerous weapon by a restricted person, a third degree felony under Utah Code Ann. § 76-10-503(2) (1990). We affirm.
Belgard asserts that the trial court erred in admitting into evidence a handgun found in his possession. We previously affirmed defendant’s conviction because he failed to object to the admission of the gun at trial. He waited until after he was convicted to raise any claim that the gun was improperly seized and moved to suppress the evidence as part of a motion to arrest the conviction. We held that Belgard had waived his claim under rule 12 of the Utah Rules of Criminal Procedure, and had not made any showing why relief from that waiver should be granted as required by rule 12.
See State v. Belgard,
FACTS
On March 2, 1989, Belgard and his wife were videotaped while meeting with an undercover agent to discuss selling a handgun to the agent. When Belgard arrived at the meeting, he removed the gun from beneath his shirt. Despite the agent’s offer to buy the gun, Belgard refused to sell because he still had “a couple of jobs” he wanted to do with the gun. Belgard left the meeting carrying the gun in the waistband of his pants.
The next day, a man and a woman attempted to trade a VCR and a handgun for a used car at a dealership. Their offer was declined and they left. The salesman later noticed that the keys to the car were missing, and that night the car was stolen. The next day, an employee of the dealership saw the stolen car pull into a motel. When the police responded, they located the car in unit four’s carport. After calling for backup and securing the area, an officer knocked on the door of unit four to investigate. The officer testified that when Bel-gard opened the door in response to his knock, he saw a gun sitting on the bed which was approximately five feet from the door. He immediately entered the room, arrested Belgard for the theft of the car, and seized the gun. It was subsequently learned that Belgard was a restricted person, which fact led to the charge and conviction involved in this appeal.
ANALYSIS
Investigation
Belgard asserts that by arresting him without a warrant, the officer violated his Fourth Amendment rights to be free from unreasonable seizures.
See generally Payton v. New York,
The trial court denied Belgard’s belated motion to suppress. It found that the officer approached unit four as part of his ongoing investigation of the car theft. When reviewing a trial court’s refusal to grant or deny a motion to suppress, we will not disturb the trial court's factual findings unless they are clearly erroneous.
State v. Palmer,
Belgard asserts that the officer had probable cause to obtain an arrest warrant once he located the stolen car outside of unit four, and therefore was required to cease his investigation without ever approaching the unit. The state counters that the officer did not have probable cause before approaching unit four. We need not decide whether the officer had probable cause because a police officer’s authority to investigate suspicious activity in a nonin-trusive manner is not governed by the presence or lack of probable cause. Belgard apparently assumes that since a police officer may approach a person to investigate suspected criminal activity even though the officer does not have probable cause to make an arrest,
Terry v. Ohio,
The Utah Supreme Court held in
State v. Folkes,
When a police officer sees or hears conduct which gives rise to suspicion of crime, he has not only, the right but the duty to make observations and investigations to determine whether the law is being violated; and if so, to take such measures as are necessary in the enforcement of the law.
Id. See also State v. Whittenback,
We hold that the officer in this ease was not constitutionally prohibited from knocking on the door of unit four as part of his investigation. To require police officers to make a probable cause determination before proceeding with the next step of an investigation, or risk suppression of any evidence obtained once probable cause might be established, would unduly impede the legitimate investigative powers of law enforcement. It would also discourage thorough investigations before warrants are sought. Such a rule would decrease, *823 rather than increase, police efforts to obtain accessible information before intruding upon a suspect’s privacy. 3
Seizure of the Handgun
The officer’s knock at unit four’s door in order to investigate suspicious activity was not constitutionally intrusive.
See Terry,
Even though it was permissible under the open view exception for the officer to observe the occupants and contents of unit four, the open view exception alone did not permit a warrantless intrusion into Bel-gard’s room. When evidence is in open view from outside a protected area, there must be “some additional legal predicate for the intrusion necessary to effect the seizure.”
Brown v. State,
When an officer is justified in believing that the individual whose suspicious behavior he is investigating at close range is armed and presently dangerous to the officer or others, it would appear to be clearly unreasonable to deny the officer the power to take necessary measures to ... neutralize the threat of physical harm.
Terry,
In challenging the trial court’s finding of exigent circumstances, Belgard erroneously focuses on the circumstances existing before the officer approached the door of unit four. He asserts that since both exits to the unit were covered by officers, there could be no exigent circumstances requiring an intrusion into the unit. Bel-gard’s argument is misdirected. The trial court properly looked to the circumstances after the officer permissibly approached the unit as part of his investigation, when Belgard opened the door and the officer saw the occupants and the gun. The trial court therefore made the proper inquiry in ascertaining whether “the procurement of a warrant [at that point in time] would have jeopardized the safety of the police officers_”
Larocco,
Prejudice
Moreover, Belgard has failed to show that the admission of the handgun prejudiced the outcome of his case. “In order to constitute reversible error, the error complained of must be sufficiently prejudicial that there is a reasonable likelihood of a more favorable result for the defendant in its absence.”
State v. Featherson,
The videotape of Belgard discussing the possibility of selling the gun to the undercover agent and the testimony of several witnesses were admitted without objection at trial. The eyewitness testimony clearly established that Belgard arrived at the meeting with the gun, possessed and exercised control over the gun at the meeting, and left the meeting with the gun.
See State v. Heaps,
Given the uncontroverted and untainted evidence, as well as Belgard’s concession that he possessed the gun, there is no reasonable likelihood of a more favorable result if the gun were suppressed.
Echevarrieta,
CONCLUSION
The police officer was not constitutionally prohibited from knocking on Beigard’s *825 Belgard door as part of his investigation, fails to challenge the trial court’s finding that when Belgard opened the door there existed exigent circumstances leading to the seizure of the gun. He also fails to show that the admission of the handgun into evidence prejudiced the outcome of his case.
We therefore affirm Belgard’s conviction.
GREENWOOD and ORME, JJ., concur.
Notes
. Belgard also claims that his arrest violated his rights under Article I, section 14 of the Utah Constitution, which contains language virtually identical to that of the Fourth Amendment. Because Belgard makes no separate analysis, we do not engage in an independent state constitutional discussion.
See State v. Collard,
. This is the only Fourth Amendment claim briefed by Belgard and therefore is the only issue we address.
. Not only would such a restriction place a tremendous burden upon the police, it would place a significant burden upon the courts as they would be required to pinpoint when probable cause could have first been established. This would be an impossible task in complex cases where numerous officers are simultaneously investigating different aspects of a case.
Furthermore, it would be logically inconsistent to require police officers to make probable cause determinations before proceeding with an investigation, given the fact that the demand for the issuance of a warránt by a neutral magistrate is based upon the premise that police officers often cannot impartially determine whether they have probable cause.
Payton,
. Our discussion of the "open view” doctrine should not be confused with the "plain view” doctrine inasmuch as the former is a "pre-intru-sive” exception and the latter is a "postintrusive” exception, and the requirements for each are different.
See generally Brown v. State,
. While a review of the trial record reveals the possibility that Belgard raised additional Fourth Amendment concerns in the trial court, no other challenges have been briefed or raised on appeal. We therefore restrict the scope of our analysis to the issues properly raised.
See Larocco,
. Rather than argue that he was not in possession of the gun, which would have been difficult given the uncontradicted evidence that he was, Belgard's trial strategy was to claim that the gun was inoperable due to its age and condition and therefore was not a dangerous weapon.
See State v. Davis,
