I'm hearing a .40 cal pistol, barrel is likely approx. 3"-5.5". I'm hearing a distance of 125-150 yards. I'm hearing 3 shots fired at maximum. Moving car? Moving target? Wind? IDK. But unless this guy is a world class professional trick shot artist with an expensive and highly accuratized custom pistol, excellent ammo and he had plenty of time for training to practice for the slope/drop from he shot to where the victims were....
I just want to chime in and say that I think everyone is over-reacting to this
125 yrds is not such a ridiculous range for a pistol (assuming a full size, high quality one) that you would need to be "world class" or have anything custom to hit human sized targets with 2 out of 3 shots. Especially if you factor in a little luck
If it was a good quality full size pistol then I would put the shooter into the category of a "good" to "very good" shooter.
There are plenty of war vets, ex LEO, hunters, casual target shooters etc that can hit a target at 100+ yards with a pistol reliably. So yes they have plenty of shooting experience but they aren't in a world class category
If you want to see something "world class" then you can watch Karl Lippard hit 8/10 @ 600 yards with an iron sight (custom) 1911 and factory ammo
https://www.youtube.com/watch?v=fV17c5A0gQA
You'll also find plenty of military stories of documented kills past a couple hundred yards with handguns. Yes they are outside the norm but this is all well beyond the range you guys are talking about
I'm a very casual shooter and I used to be able to hit 12 inch targets out to 100 yards with my 1911. Pretty easy if you're benched or have something to rest on, pretty hard if free standing.
So assuming he was in the car, was able to rest the gun on the door, and was using something like a full size Glock I think it's 100% believable even for a not super skilled shooter.
You have to remember the reason police can't hit their targets in a crisis is because of the adrenaline and other factors in the environment. Especially if there is concern of the other side shooting back that changes everything and unless your heavily trained and conditioned for it your accuracy is going to go out the window. Some guy sitting 125 yrds away in his car is not going to have those concerns
EDIT: Here's some dude pegging a soda bottle @ 100 yards with what I assume is a stock Glock 23 (.40 cal COMPACT) free standing. Again would be a lot easier from a rested position!
https://www.youtube.com/watch?v=Sw8hTmCGo44