Even if he didn't draw his weapon, if you're fighting with police and they find that you have a gun on you, you're likely to get shot and that will be justifiable every day if the week. The shooter needs to show that he had a reasonable fear of imminent death or great bodily harm. That fear does not need to be correct, only reasonable (I.e. not speculative). A prosecutor would need to prove, beyond a reasonable doubt, that lawful grounds for the use of deadly force did not exist. The above, however, assumes an unbiased jury and judge, which is practically impossible in Minnesota currently (see Chauvin and fentanyl Flloyd). It won't come down to a Minnesota court though, due to federal law enforcement involvement. The Feds will tell MN to fuck right of.