If there were two shooters than why did the ear witnesses describe shots being consecutive, not simultaneous? They describe distinct shots from one gun and then the other - if it was TWO shooters they would have been shooting at the same time with each gun - one shooting Skyla, one shooting Taylor - and each girls would have been shot with only ONE gun. Plus each girl would have been shot from a similar distance - it's obvious from the autopsy that the killer was standing much further from Skyla than Taylor initially. Two shooters would make each shot on each girl made from the same distance - not one up close and one 10 - 15 feet away.
To see how fast this would have happened just think - each shot takes one second. Taylor was shot 1st - once = 2 seconds, then turn slightly right, shoot Skyla, 4 times = 8, maybe 10 seconds, then turn back and shoot Taylor again = 2 seconds. Both girls are now down on the ground 1st gun = 15 seconds. Switch guns, maybe = 5 seconds, approach and shoot Taylor twice = 10 seconds, approach Skyla, shoot 4 times = 15 seconds. second gun = 30 seconds.
Total time elapsed from 1st shot to last - one minute - with one shooter. Which is what the ear witnesses heard.
It doesn't take that long to shoot someone - especially when you are as close as the killer was to Taylor and Skyla when he pulled the 1st gun out. As fast as you can bend your finger, you can shoot.
So the killer killed 2 girls in a minute - say he went to check both girls, make sure they are dead (or mortally wounded) - another 30 seconds, maybe a minute. Wipes his hands off, throws guns in bag or trunk or wherever, takes off his bloody shirt, throws it in with the guns, gets in his car and drives away. 2 minutes tops and he's outta there. Off to dump the shirt and the guns somewhere and then home to get out of the other clothes and get rid of them, clean up. He was probably relaxing at home with a beer before sunset.
So if he's pretty cold (which we assume he was) - he is at the scene maybe 5 minutes. That's all. One shooter, no witnesses, job done, 5 minutes and he's home free. Nobody to tell - rat him out or get nervous. If it was two shooters I surmise one of them would have started cracking by now which is why most good criminals who aren't in prison don't do stuff like this in pairs, they don't TRUST other people to keep quiet. They do it alone, and I think this killer did. He had two guns, (and maybe more) because he wasn't sure of the target or if he'd need more firepower or maybe have to shoot his way out of something---since he didn't - might as well use BOTH the guns on the girls, confuse the cops a little.
My Opinion