Based on the latest information we have been given, I do believe the perp is a woman. This doesn't mean this wasn't a hit. She could be connected to MB in some way (CG, gym, etc.) or not (we may not even be aware of her at this point--she may not be listed on the SW, she may not even be someone we are currently aware of).
I know most of us don't usually hear of "hitwomen," but just because she is female and has a small stature does not mean she wouldn't be capable. Perhaps she has a military background, mental health issues, and/or is in desperate need of money OR this could be a situation many of WS have supposed, where it is not a hit and this woman has some kind of extreme anger or personal vendetta towards MB. Again, just because she's a woman and may have children does not mean we should assume a husband would be there to wonder where she is at 2 AM or that her children would be left home alone. Perhaps she's a single mother, and shares custody. Maybe she didn't have her children on the weekend or that week. Maybe she does not have children.
I believe this Nissan IS her car, and police know this from the survellience they have from the gun store. My guess is that this is when she first attempted to break-in at the church, and she hid briefly in the gun store's parking lot, waiting to see if an alarm went off (as others have mentioned). There is no doubt this murder was incredibly well-planned; however, pulling into that parking lot, no matter how briefly (2 min?) may just be her downfall.
As for why her car was seen so early before she was first seen on cameras at the church, I think it probably took her longer than we might imagine, especially if she is a small (ish) woman, even if incredibly strong, to break in to a church in the dark, rainy, early hours of the morning (plus she may have needed time to change into the SWAT costume once inside).
As for why police aren't sharing more information with us, I agree with everyone who is saying they think police know who this car belongs to, and based on forensic analysis of the survellience this woman's description matches the perp; however, they still may not have a motive or a connection between MB and this person. They may still need MORE before they let this woman know they are "on" to her IMO. They are wanting someone to contact them so they can get more information on the perp, and perhaps (just a hunch) make a connection between this woman and another person who may be involved (IF this is indeed a hit).
JMO
