If targeted, why not kill Missy at her house, or close to her house? If targeted, they'd know her hubs was out of town. If targeted, they'd know the reason Missy was going to the church: to lead an exercise class i.e. they'd know several people were going to be there.
If Missy was targeted, the church makes far more sense than elsewhere.
Harder to break into a house with multiple occupants and nearby neighbours vs a somewhat isolated, unoccupied church without being detected in situ, greater chance Missy would be able to access firearm for defence and utilise her greater familiarity with her surroundings, higher likelihood of witnesses (her daughters, then neighbours). Gunshot sound more likely to be heard by family or neighbours so LE could be notified/get there quicker. Amount of quick exit routes - less viable / level of traffic lower so getaway vehicle may stand out more? If, as I lean towards, they were trying to frame the scene as a burglary gone wrong, this may be a harder sell if it occurred at her house, crime may immediately seem more personally motivated etc. Outside chance - but maybe the perp didn't want her daughters to be the ones to find Missy?
Why not near house - harder to kill when on the move and no fixed location, harder to plan; more variables to account for to avoid detection, smaller window of opportunity. An idle thought - if she had been killed on her driveway, the case would be perhaps be similar to Liz Barraza.
If targeted they likely would know how much earlier Missy would be there at the church to set up before anyone else arrived, knew she would have to unlock the church so toilet facilities were available or would be situated under the awning. It was a location they could arrive at BEFORE Missy arrived, to get prepared. It was a place that could be cased in more detail than her home without suspicions before the crime, and the day of the crime. E.g. they could attend the church - in whatever capacity - to learn the layout, drive around it, sit in the car park across the road at different times of the day to check traffic etc. with an easier cover story than accessing Missy's house (unless they were already intimately familiar and had a legitimate excuse to be there).
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I'm not married to the targeted theory, but untargeted makes far less sense to me. Because it doesn't make sense that the perp was there to steal stuff - they probably wouldn't have worn so much bulky clothing to hide their appearance, they would've actually taken valuables, they would've been in and out as fast as possible.
If they broke in to LARP as SWAT or wanting to be "tacticool", I don't think that's reflected in their lackadaisical wandering. They were not pretending to breach and clear along the halls, they weren't using tools or weapons in a way that LE or a video game character would in the footage we've seen.
If they broke in just for the thrill/to cause property damage/idle exploration and they were worried that there was a witness to their crime, why murder Missy - and make the crime FAR more severe in the process - rather than just run away? So it seems most logical that the murder would have likely occurred in the moment when they were panicked, right?
But from what I remember, Missy was shot AND also had multiple puncture wounds to the head and chest from a "tool". While possible if simply surprised, it seems like overkill; why continue the attack with a different weapon? That goes beyond spur of the moment reaction. Why not get the hell out of there as soon as she was down if the perp's main fear was being caught?
So, if untargeted... Maybe the person was there to kill someone that morning, they just didn't care who? But then if they were at the church at that time, they would have to know the class was on that morning, otherwise what potential victims could there be there, at 4am at a church? Therefore, if the perp knew there was a class on, they would also know the class was guaranteed to continue OUTSIDE even if it was raining. So why break into the church wearing SWAT gear and remain inside, waiting for them to arrive, when it was far more likely that all the possible victims would remain outside? It would be far harder to get away, way more likely people would see you than say, taking pot shots when they were grouped together outside.
