They've been begging for the public's help in IDing BG by the sound of his voice.
If this is the beginning sequence of events,
Who said, "Guys, ... ?"
Maybe BG then gives a command that we hear as glass breaking static.
Perhaps, BG offers s/t like, "Guys, they're headed your way." Or, "Guys, you can't get away." Then, we hear the infamous:
"Down the Hill."
It's bone chilling, really. Those brave, precious, pretty, young girls, RIP.
GreyHuze stated he can share that Abby is heard on the audio asking, "Is that a gun?" If true, and there's every reason to believe it is, then the firearm is how control over 2 girls was managed.
.