¶1OPINION
¶2In November 1997, Bret F. Maness killed Delbert White during a confrontation in front of Maness's apartment. While the reasons for the confrontation are disputed, it is clear *1130that on November 21, 1997, White went to Maness's apartment with a two-by-four to confront Maness. Maness lived in a ground-level apartment with his wife, Tina Maness. A friend, Paul Hackett, lived in the apartment below the Manesses. Maness was in his apartment with Hackett when White arrived at his door. In the subsequent confrontation, which started in Maness's residence and ended in the driveway, Maness shot White. When police and paramedics arrived at the scene, White was lying in a pool of blood. The paramedics took White to a hospital, and the police took Maness and Hackett into custody. The police entered both Maness's and Hackett's apartments to look for other possible victims or suspects. When the police entered Maness's apartment, they saw weapons and marijuana plants. The police applied for a search warrant based on their observations and seized evidence.
¶3The incident resulted in Maness being charged with murder in the first degree
a) maintaining a structure used for keeping or distributing controlled substances,4
b) possessing one pound or more of mariJuana,5
c) possessing with intent to deliver one ounce or more of marijuana,6 and
d) possessing twenty-five or more marijuana plants.7
¶4Maness defended the murder charge by contending that he acted in self-defense. The jury acquitted Maness of the murder charge and all lesser offenses that arose out of the death of White. But the jury convict, ed Maness of possession of a firearm during the commission of a felony drug offense and two counts of misconduct involving a controlled substance in the fourth degree: one for maintaining a structure used for keeping or distributing a controlled substance and a second for possession of one pound or more of marijuana. The jury acquitted Maness of the other drug charges.
¶5Judge Souter sentenced Maness to a composite sentence of eight years with three suspended: six years with two years suspended for possessing a firearm during the commission of a felony drug offense and two years with one year suspended on each conviction of misconduct involving a controlled substance in the fourth degree (to run consecutively to the weapons possession sentence). Maness appeals his convictions, raising several arguments. We reverse Maness's conviction for possession of a firearm during a felony drug offense. We otherwise affirm his convictions.
¶6Mamess's motion to suppress evidence that the police obtained from entering his residence
¶7Following his indictment, Maness filed a motion to suppress the evidence the police obtained when they entered his residence. The state contended that the search was justified by the protective sweep exception to the warrant requirement-that the police needed to enter Maness's residence because they had reasonable cause to believe that their safety was in danger from additional suspects who posed a threat to officers at the seene. The state also claimed that the search was justified by the emergency aid exception to the warrant requirement-that the police needed to search Maness's residence to make sure other people had not been injured. Following an evidentiary hearing, Judge Souter accepted the state's contention that the search was justified because the police had reasonable cause to believe that their safety was in danger, and *1131thus was permissible under the protective sweep exception. Therefore he denied Maness's motion to suppress. Judge Souter, however, rejected the state's contention that the search was justified under the emergency aid exception. Maness appeals Judge Souter's denial of his motion to suppress.
¶8In Alaska, to prove a search falls within the protective sweep exeeption to the warrant requirement, the state must prove that:
1) before engaging in the search, the officers had reasonable cause to believe that their safety was in danger because additional suspects-beyoud those under police control-were present and posed a threat to the officers and
the search was narrowly limited to areas where the officers could find dangerous persons.8
¶9Judge Souter found credible the police testimony that their safety was in danger and their search was narrowly limited. At that hearing, Anchorage Police Officer Richard Jensen testified that he received a message from the dispatcher that a shot had been fired and that an individual was injured at 3804 Lois Drive. As he approached the scene, a uniformed security guard, Edward Spencer, pointed to the scene and said that a crazy man was down the street with a shotgun. Jensen proceeded to the scene and saw Maness with a rifle. Officer Jensen pointed his handgun at Maness and ordered him to drop the gun, which Maness did. Jensen and other officers saw White lying face down on the driveway in a large pool of blood. The police took Maness and Hackett into custody, and paramedics arrived to treat White. According to Lt. William Gifford, the police also had been told that earlier someone in Maness's residence had been shooting towards another residence with a pellet gun or a'.22 and that White had come over to Maness's residence because of this earlier shooting incident. Lt. Gifford made the decision to enter the two apartments at 3804 Lois Drive because he was concerned that other armed suspects might be in the apartments or that there might be additional victims.
¶10Judge Souter concluded that this information justified the police entering Maness's and Hackett's apartments, which were adjacent to the driveway. He found the police had information of an earlier shooting incident and a report of a crazy man with a shotgun. This information gave the police reasonable cause to believe that their safety was in danger because additional suspects might be within the apartments. He also found that the officers had narrowly limited their search to a reasonable area. And he found it was reasonable for the police to have entered the residences thirty minutes after they had arrived at the scene because the officers had several different things that required their attention before they could search-a victim who was dying, a erowd forming, and other officers arriving at the scene. Judge Souter concluded the thirty-minute. wait did not undermine the contention that the search was necessary for officer safety.
¶11We conclude that Judge Souter did not err in denying Maness's motion to suppress. His findings support the conclusion that the police had reasonable grounds to conduct a protective sweep of Maness's residence.
¶12The instruction on misconduct involving weapons in the second degree
¶13The jury convicted Manegs of miscon-duet involving weapons in the second degree. Alaska Statute 11.61.195(a)(1) prohibits the possession of a firearm during the commission of a felony drug offense:.
(a) A person commits the crime of misconduct involving weapons in the second degree if the person knowingly '
(1) possesses a firearm during the commission of an offense under AS 11.71.010-11.71.040 [misconduct involving a controlled substance in the first, second, third, and fourth degrees].
¶14This case is controlled by Collins v. State.
¶15On appeal, Maness points out that Judge Souter's jury instruction conflicts with {our decision in Collins. The state argues that we should overrule Collins, but we decline to revisit our decision. We note that this court has continued to follow Collins in both Lewis v. State
¶16The state also argues that the evidence presented at trial established a nexus between Maness's possession of a firearm and his drug offense of maintaining a dwelling for the purpose of keeping a controlled substance. The problem with the state's argument is that it merely establishes that a properly instructed jury could have returned a verdict favorable to the state on this count. But Judge Souter's instruction did not allow the jury to consider the nexus element of the offense. To affirm Maness's conviction, we would have to find that the error in failing to instruct the jury on the nexus element was harmless beyond a reasonable doubt.
¶17The instruction on maintaining a structure used for keeping controlled substance
¶18Maness argues that Judge Souter plainly erred in how he instructed the jury on the charge of maintaining a structure used for keeping controlled substances.
¶19Alaska Statute 11.71.040(a)(5) states:
(a) Except as authorized in AS 17.30, a person commits the crime of misconduct involving a controlled substance in the fourth degree if the person
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(5) knowingly keeps or maintains any store, shop, warehouse, dwelling, building, vehicle, boat, aireraft, or other structure or place that is used for keeping or distributing controlled substances in violation of a felony offense under this chapter or AS 17.30[.]
¶20Judge Souter instructed the jury that Maness could be convicted of violating AS 11.71.040(a)(5) if the jury found the state proved:
First, the event in question occurred at or near Anchorage and on or about November 21, 1997; and
Second, that ... Maness knowingly used or allowed another to use the ... dwelling ... for keeping or distributing controlled substances in violation of a felony offense as charged in Count V, VI or VII of the indictment; and
Third, that [Maness] knew said dwelling ... was used for keeping or distributing controlled substances.
¶21Maness did not object to the jury instruction.
¶22On appeal, Maness argues the state had to prove as an element of AS 11.71.040(a)(5) that a substantial purpose of the dwelling was for keeping or distributing controlled substances, the activity prohibited under the statute was ongoing or continuous (not a *1133single, isolated instance), and the possession of the controlled substance was not merely for personal use.
¶23This court summarized the required elements of AS 11.71.040(@a)(5) in Dawson v. State:
[TJlo - establish a violation of AS 11.71.040(2)(5), the state must prove that the accused, while knowingly controlling or knowingly having authority to control property of the type listed in the statute, personally used the property or knowingly permitted another person to use it for the purpose of keeping or distributing prohibited controlled substances in a manner that amounts to a felony under Alaska law. The state need not prove that the property was used for the exclusive purpose of keeping or distributing controlled substances, but such use must be a substantial purpose of the users of the property, and the use must bé continuous to some degree; incidental use of the property for keeping or distributing drugs or a single, isolated occurrence of drug-related activity will not suffice. The purpose with which a person uses property and whether such use is continuous are issues of fact to be decided on the totality of the evidence in each case; the state is not required to prove more than a single specific incident involving the keeping or distribution of drugs if other evidence of continuity exists.16
¶24It is uncontested that Maness was growing a substantial amount of marijuana. When the state stripped and dried the plants, they yielded approximately 8.7 pounds of marijua~ na. The evidence presented at trial established that Maness used a substantial amount of his living space to grow marijuana. Because Maness had a marijuana growing operation, it seems apparent that the presence of the marijuana in his residence was not a "single, isolated occurrence of drug-related activity" but was a continuous growing operation.
¶25Maness points out that the jury rejected the count charging Maness with possessing marijuana for purposes of distribution. He argues that he should not be convicted of maintaining a structure used for keeping a controlled substance when the jury did not find that his possession was for anything other than personal use. But, AS 11.71.040(a)(5) prohibits knowingly keeping or maintaining a dwelling "that is used for keeping or distributing controlled substances in violation of a felony offense." The plain language of the statute appears to eriminalize behavior beyond maintaining the structure for distributing controlled substances.
¶26We are to find plain error only when we conclude that the error was so obvious that any competent attorney would have been aware of the issue and objected and that the defendant was obviously prejudiced by the failure to raise the issue.
¶27In a related argument, Maness contends that the evidence the state presented at trial was insufficient to support his conviction under AS 11.71.040(a)(5) because he possessed the marijuana for his personal use. But, as we pointed out above, the statute does not restrict the crime only to instances where someone maintains a structure for purposes of distributing a controlled substance.
¶28The jury instruction on misconduct involving a controlled substance in the fourth degree for possession of a pound or more of marijuana
¶29The state charged Maness with violating AS 11.71.040(a)(8)(F), which prohibits possession of "one or more preparations, compounds, mixtures, or substances of an aggregate weight of one pound or more containing a schedule VIA controlled substance." The jury found Maness guilty of this charge. Maness objects to the instruction Judge Souter gave to the jury. He points to testimony that only a small portion of the marijuana plant, "the bud," was commonly used as marijuana. He contends that under *1134Judge Souter's instruction, the jury could have considered more than the weight of the marijuana bud in calculating the weight of a live marijuana plant under AS 11.71.040(a)(B)(F), which was error.
¶30This issue requires analysis of three statutory sections: AS AS 11.71.080, and AS 11.71.900(14). The first, AS 11.71.040(2)(8)(F), criminalizes the possession of a pound or more of marijuana. The second, AS 11.71.080, states, "For purposes of calculating the aggregate weight of a live marijuana plant, the aggregate weight shall be the weight of the marijuana when reduced to its commonly used form." And, the third, AS 11.71.900(14), defines "marijuana" as "the seeds, and leaves, buds, and flowers of the plant" but not the resin or oil from the plant, the stalks, or sterilized seeds.
¶31Judge Souter instructed the jury:
"Marijuana" means the seeds, leaves, buds and flowers, but not the stalks or roots of the marijuana plant ... whether growing or not. ,
For purposes of calculating the aggregate weight of a live marijuana plant, the aggregate weight shall be the weight of the marijuana when reduced to its commonly used form.
¶32Further, he instructed the jury that to con-viet Maness under AS 11.71.040(a2)B)(F), it had to find that he "knowingly possess[ed] an aggregate weight of one pound or more of ... [a] compound[] ... containing ... marijuana."
¶33Maness contends that Judge Souter erred in giving this instruction. He argues that the testimony .at trial established that only the bud of a growing marijuana plant would normally be used as marijuana. Therefore, the evidence at trial established that marijuana, when reduced to its commonly used form, is only the bud. He argues that Judge Souter erred in allowing the jury to consider the weight of other parts of the marijuana plant, such as the leaves, when considering whether he "knowingly possess[ed] an aggregate weight of one pound or more of ... [a] compound[] ... containing ... marijuana."
¶34We conclude that Judge Souter did not err in giving the instruction. In Gibson v. State,
¶35In Atkinson v. State,
¶36More recently, in Pease v. State,
To determine whether the grower possessed one pound or more of marijuana, the police could not simply cut down the plants and weigh them. In practice, the police had to finish the job that the grower had begun-that is, they had to cut down *1135the plants, allow them to dry, and then cut the leaves, buds, and flowers from the stalks-if they were to prosecute the grower under AS 11.71.040(2)(8)(F).26
¶37Here, the state presented evidence that although the bud of the plant is the most marketable and desirable form of marijuana, the leaves of the plant have value and are used by marijuana users. Furthermore, the statutory definition of marijuana includes "the seeds, and leaves, buds, and flowers" of the marijuana plant.
¶38Sufficiency of the evidence for the charge of possessing a pound or more of marijuana
¶39Maness next contends that the state did not present sufficient evidence for the jury to convict him of possessing one or more pounds of marijuana. Maness renews his argument that the jury only should have considered the bud from the live marijuana plants in determining its aggregate weight. We reject that contention above. Maness also contends that some of the marijuana weight was due to non-consumable marijuana and non-marijuana objects (dimes, a nail, stalks, stems, roaches, and charred material).
¶40The state presented evidence that the marijuana seized from Maness's apartment weighed approximately 4.18 pounds. The marijuana that was packaged with unuseable materials weighed 7.66 ounces. Therefore, excluding the packages that contained foreign objects and non-usable marijuana, the state presented evidence that Maness possessed 3.7 pounds of "usable" marijuana (excluding seeds, stems, stalks, and other non-usable portions of marijuana).
¶41The state presented sufficient evidence for a reasonable juror to conclude beyond a reasonable doubt that Maness possessed "one or more preparations, compounds, mixtures, or substances of an aggregate weight of one pound or more containing" marijuana and that the marijuana that came from live plants had been reduced to its commonly used form.
¶42Presentence report and sentencing issues
¶43Maness raises several issues concerning contested items that were included in the presentence report and sentencing issues. Because we are reversing Maness's conviction for misconduct involving weapons in the second degree and remanding the case, we find it unnecessary to address these issues.
¶44Conclusion
¶45Maness's conviction for misconduct involy-ing weapons in the second degree is REVERSED. His two convictions for misconduct involving a controlled substance in the fourth degree are AFFIRMED.
¶46. AS 11.41.100(a)(1)(A).
¶47. AS 11.61.195(a)(1); AS 11.16.110(2)(B).
¶48. AS 11.71.040(a).
¶49. AS 11.71.040(a)(5); AS 11.16.110(2)(B).
¶50. AS 11.71.040(a)(3)(F); AS 11.16.110(2)(B).
¶51. AS 11.71.040(a)(2); AS 11.16.110(2)(B).
¶52. AS 11.71.040(a)(3)(G); AS 11.16.110(2)(B).
¶53. See Earley v. State, 789 P.2d 374, 376 (Alaska App.1990); Murdock v. State, 664 P.2d 589, 596 (Alaska App.1983); State v. Spietz, 531 P.2d 521, 525 (Alaska 1975).
¶54. 977 P.2d 741, 752-53 (Alaska App.1999).
¶55. See id. at 753.
¶57. 9 P.3d 1028, 1037-38 (Alaska App.2000).
¶58. 12 P.3d 784, 794-95 (Alaska App.2000).
¶59. See Carman v. State, 658 P.2d 131, 136 (Alaska App.1983).
¶60. 894 P.2d 672 (Alaska App.1995).
¶61. Dawson, 894 P.2d at 678-79 (footnote omitted).
¶62. See Wolfe v. State, 24 P.3d 1252 (Alaska App.2001).
¶63. 719 P.2d 687 (Alaska App.1986).
¶66. 869 P.2d 486 (Alaska App.1994).
¶70. 27 P.3d 788 (Alaska App.2001).
¶71. Id. at 788-89.
¶72. AS 11.71.900(14).
¶73. AS 11.71.040; see AS 11.71.080.