I downloaded the mp3 off this twitter video from Katy Perrys feed and reversed it and it sounds like "Shoot Shoot Shoot" and has Sirens Ringing.

This was uploaded 4 times the last one being 28 minutes before the attack. Her album is called "West Coast Witness".

You might find the audio a little disturbing.

Tweet On May 21st

Tweet On May 22nd Highlighting the importance of her being a woman. Remember it was women and children who were murdered.

Strange Audio Tweet On May 22nd that doesn't make sense.

Reversed audio

What do you guys think?