For those who aren't following my Fargo motive: Missy knew something. The reason SWATPERP had to ambush her and have a few minutes with her alive, rather than shoot her, was to get the information out of her. Then they killed her like in Fargo Season 2 to the upline lady in the MLM. This may not hold water because all they had to do to get info out of Missy was probably kidnap or threaten one of her kids, but maybe they didn't have much time and were waiting for their chance to quickly find out who knew the information they wanted (in Fargo they got it by listening in to a phone call, I think) and they were motivated to pounce QUICK, plus, they were so angry and bent on revenge, they were out for blood, even though the upline lady wasn't their ultimate target.