(concurring in part and dissenting in part).
The trial court erred in refusing to instruct the jury on trespass, justification of force to prevent trespass, defense of others, and mistake of fact. The majority affirms that error.
1. Trespass Instructions.
Frey proposed Instructions # 2 and # 3. These instructions defined trespass and justification of force to prevent trespass under SDCL 22-18-4.* The trial court refused these instructions. Instead, the court instructed the jury, over Frey’s objection, that an officer acting within his authority is ordinarily not trespassing when investigating a crime upon private property-
To support the trial court’s instruction, the State cites the general rule in State v. Cook, 319 N.W.2d 809 (S.D.1982):
Conduct otherwise a trespass is often justifiable by reason of authority vested in the person who does the act, as, for example, an officer of the law acting in the performance of his duty.
Id. at 812 (citing 75 Am.Jur.2d Trespass § 43 (1974)). Courts have recognized the rule that “Ordinarily, an officer of the law who goes upon private property while investigating a crime is not a trespasser.” Id. at 812. See United States v. Barnett, 492 F.2d 790 (5th Cir.1974); State v. Van Rees, 246 N.W.2d 339 (Iowa 1976); State v. Lukus, 149 Mont. 45, 423 P.2d 49 (1967). However, this rule is not without limitation. The Van Rees court stated:
We hold [the officer] was entitled to enter defendant’s premises to carry out this duty. For this limited purpose he was *729not a trespasser and did not require defendant’s consent.
What we have said does not, of course, permit an officer to enter one’s home or to conduct a search or make a seizure without a warrant or other authority.
Id. at 343.
The undisputed evidence showed the officers did not possess a search warrant, and that Roland requested the officers to leave the property. Although there is some testimony that the Freys consented to the search, there is also evidence indicating that the Freys did not consent to the officers’ presence and search on the property. Under these circumstances, the court could not properly conclude, as a matter of law, that the Freys consented to the search.
The plain view exception is inapplicable under these facts. Plain view requires that the evidence is discovered inadvertently, in other words that the officer did not know in advance the location of the evidence. Texas v. Brown, 460 U.S. 730, 103 S.Ct. 1535, 75 L.Ed.2d 502 (1983). This discovery was not inadvertent, as the officers went to the Frey ranch for the sole purpose of searching for the animals mentioned by the anonymous tip. Unable to determine the species of the animals from the highway, the officers waited and followed Roland up the driveway before proceeding onto the property. This indicates knowledge on the part of the officers that an unwarranted search was illegal and evidences a lack of good faith, another requirement of plain view. Brown, supra.
Finally, the State has not shown other exigent circumstances justifying the war-rantless search by the officers. State v. Bennett, 295 N.W.2d 5 (S.D.1980); State v. Max, 263 N.W.2d 685 (S.D.1978). The trial court held that a search warrant was unnecessary under SDCL ch. 41-15, which relates to enforcement powers and procedures for the Department of Game, Fish, and Parks. Although these provisions purport to grant broad powers for warrantless administrative searches, these provisions cannot exceed the protections afforded by the constitution. State v. Stip, 246 N.W.2d 897 (S.D.1976).
South Dakota has created a statutory privilege to use reasonable force to protect persons or property under SDCL 22-18-4. The trial court should have instructed the jury on this potential justification to aggravated assault, as the facts raised a jury question regarding consent to the trespass and the reasonableness of the force used under the circumstances. The trial court erred in concluding, as a matter of law, that the warrantless search was justified under these provisions and that the officers were acting within their lawful and official duties.
2. Defense of others and mistake of fact instructions.
The trial court denied Frey’s proposed instructions on defense of others and mistake of fact. “[A] defendant in a criminal case is entitled to an instruction on his theory of the case if there is evidence to support it and a proper request is made.” United States ex rel. Means v. Solem, 646 F.2d 322, 328 (8th Cir.1980). “If instructions on self-defense or defense of others are supported by the evidence, they are necessary and it is error not to give them.” State v. Huber, 356 N.W.2d 468, 474 (S.D.1984). Defense of his brother and mistake of fact was relied upon by Frey and he made a proper request for the instructions. Although Frey was not entitled to a self-defense instruction because of insufficient evidence, there was sufficient evidence to support defense of others and mistake of fact instructions.
Frey testified that he grabbed his shotgun before leaving the house because he believed his brother was in danger. This testimony is supported as both parties testified that a great deal of arguing, cursing, and shouting took place between Roland and the officers. The record indicates that it was dark which supports Frey’s claim that he was unable to identify the other persons as law enforcement officers. This evidence also supports Frey’s instruction on mistake of fact. While there was some testimony that Frey went beyond the reasonable force necessary to protect his brother, this determination should have been made by a jury upon proper instruc-*730tiohs and not by the court. The mistake made by the trial court and the majority is in accepting the version of the evidence most favorable to the State, rather than to the defendant. This is error when considering whether there is sufficient evidence to support jury instructions. State v. Moffett, 147 Wis.2d 343, 433 N.W.2d 572 (1989); State v. Clayburn, 223 Neb. 333, 389 N.W. 2d 314 (1986); Van Zee v. Assam, 336 N.W.2d 162 (S.D.1983); State v. Oien, 302 N.W.2d 807 (S.D.1981).
The State claims that any alleged error in refusing Frey’s proposed instructions was not reversible as prejudicial error. State v. Stapleton, 387 N.W.2d 28 (S.D.1986); Stale v. Grey Owl, 295 N.W.2d 748 (S.D.1980). In Grey Owl this court stated:
Hence, the jury should have been properly instructed thereon. The requested jury instruction was vital in properly directing the jury’s attention to a matter extremely material to the case. If the requested jury instruction ... had been given, a different light could have been placed on the victim’s testimony potentially strengthening the chances for appellant’s acquittal.
Id. at 751. The instructions on defense of others, mistake of fact, and trespass were vital in directing the jury’s attention to possible justifications for Frey’s actions. These instructions were necessary to enable the jury to consider all the evidence in a proper light. It was reversible error not to instruct on these possible justifications.
The majority presents an elaborate and detailed factual presentation of this case. In doing so, the majority fails to appreciate that this is exactly why the instructions on trespass, defense of others, and mistake of fact were necessary. As Marshall McLuhan states “the medium is the message.” The message sent by the majority is that this is a factual case and these questions should have been given to the proper fact finder, the jury, and not the court. I would reverse and remand for a fair trial on proper instructions in accordance with this writing.
SDCL 22-18-4 provides:
To use or attempt or offer to use force or violence upon or toward the person of another is not unlawful when committed either by the party about to be injured, or by any other person in his aid or defense, in preventing or attempting to prevent an offense against his person or any trespass or other unlawful interference with real or personal property in his lawful possession; provided the force or violence used is not more than sufficient to prevent such offense.