(n. 2) (2000). We are guided by an earlier decision, United States v. Ali, 63 F.3d 710 (8th Cir. 1995). In that case, the defendant was convicted of being a felon in possession of a firearm.

Possession of a firearm may be joint with another person, and it may be constructive if a defendant does not have physical possession but has power and intent to exercise dominion and control over the object. See United States v. Ali , 63 F.3d 710, 715-17 (8th Cir. 1995). Given the testimony of the cooperating witness and the expert evidence about the nexus between firearms and drug trafficking, the jury reasonably could have found that Moreno Lopez possessed a firearm in the truck, and that he did so in furtherance of a drug trafficking offense.

Casteel did not object to the district court's jury instruction regarding possession or offer a separate instruction on his “fleeting” possession theory. See United States v. Ali, 63 F.3d 710, 717 n. 9 (8th Cir.1995) ( “Because defendant failed to seek a proper instruction on his innocent possession theory, we need not, and do not, decide at this time whether an ‘innocent reasons' defense is available under § 922(g).”). And the district court permitted Casteel to argue to the jury that “touching, inspecting and negotiating a price” for the firearms in connection with Casteel's business of buying and selling used goods with Devan was not possession. Cf. United States v. Stover, 822 F.2d 48, 50 (8th Cir.1987) (deciding the defendant waived any claim of error when the district court provisionally permitted the defendant to argue innocent possession, but the defendant made no such argument).

Casteel did not object to the district court's jury instruction regarding possession or offer a separate instruction on his "fleeting" possession theory. See United States v. Ali, 63 F.3d 710, 717 n.9 (8th Cir. 1995) ("Because defendant failed to seek a proper instruction on his innocent possession theory, we need not, and do not, decide at this time whether an 'innocent reasons' defense is available under § 922(g)."). And the district court permitted Casteel to argue to the jury that "touching, inspecting and negotiating a price" for the firearms in connection with Casteel's business of buying and selling used goods with Devan was not possession. Cf. United States v. Stover, 822 F.2d 48, 50 (8th Cir. 1987) (deciding the defendant waived any claim of error when the district court provisionally permitted the defendant to argue innocent possession, but the defendant made no such argument).

This is sufficient evidence to allow a reasonable jury to find that Thompson constructively possessed the gun at that time. See United States v. Ali, 63 F.3d 710, 715 (8th Cir.1995) (approving the same jury instruction given in this case, which defines constructive possession as occurring when “[a] person who, although not in actual possession, has both the power and the intention at a given time to exercise control over a thing, either directly or through another person or persons”). Finally, with regard to count nine, Baggett argues that he cannot be convicted of conspiracy to obtain ammunition for a felon because he was not aware of “federal laws regulating the sale of ammunition to felons.”

The possession instruction given by the district court followed the Model Criminal Jury Instructions for our circuit and fairly and adequately submitted the issue of possession to the jury. See Manual of Model Criminal Jury Instructions for the District Courts of the Eighth Circuit, 8.02 (2011) (citing United States v. Smith, 104 F.3d 145, 148 n. 2 (8th Cir.1997); United States v. Ali, 63 F.3d 710 (8th Cir.1995); United States v. Johnson, 857 F.2d 500, 501–02 n. 2 (8th Cir.1988); United States v. Montgomery, 819 F.2d 847, 851 (8th Cir.1987); Sewell v. United States, 406 F.2d 1289, 1293 n. 3 (8th Cir.1969); United States v. Henneberry, 719 F.2d 941, 945 (8th Cir.1983) (including definition of constructive possession)). Because the instruction given adequately and correctly incorporated the substance of Carrasco's requested instruction, the district court did not abuse its discretion in denying it.

These “model” instructions, it must be noted, “have not been approved en masse by our court,” and are approved “only as they are individually litigated and upheld by this court on a case-by-case basis.” United States v. Ali, 63 F.3d 710, 714 n. 3 (8th Cir.1995). The district court declined to give the proposed instruction and stated:

The government could show Reed exercised dominion or control over the firearm or ammunition "either directly or through another person or persons." 8th Cir. Model Crim. Jury Instruction 8.02; see also United States v. Ali, 63 F.3d 710, 716 (8th Cir. 1995) (noting the Eighth Circuit's approval of the model instruction). The evidence presented by the government showed Reed was at the Little Shell Nation headquarters after leaving Nevada.

With respect to the question of innocent or transitory possession, we have twice declined to rule on the availability of an innocent possession defense. See United States v. Ali 63 F.3d 710, 717 n. 9 (8th Cir. 1995) ("Because defendant failed to seek a proper instruction on his innocent possession theory, we need not, and do not, decide at this time whether an `innocent reasons' defense is available under § 922(g)."); United States v. Stover, 822 F.2d 48, 50 (8th Cir. 1987) (holding that any claim of error had been waived).

See id. at 357-58. Likens did not commit a technical or accidental violation of the statute, nor, assuming without deciding that such a defense might be available in a proper case, was his possession innocent or transitory. Cf. United States v. Mason, 233 F.3d 619, 622-25 (D.C. Cir.2000); United States v. Ali, 63 F.3d 710, 716 n. 7 (8th Cir.1995). He transported the firearm and ammunition from Florida to Iowa, and he illegally used marijuana while he was in possession of the firearm. Once apprehended, he testified falsely under oath.