How do you go about submitting a video and reporting the killer ?
On console, xbox specifically, record the violation and then wait for it to appear on:
Once there, copy the URL of the video and then paste it on a ticket at:
To add to what @Nickenzie said when you go to create the support ticket select additional player report information.
You'll get 1 of 2 responses with the 1st one being they're looking into, which means basically it's backlogged atm and a mod hasn't seen it yet. This is the rarer of the 2 and usually happens at certain times of the day.
The 2nd response is thanks for your report, we'll now being investigating and they can't keep in contact with you due to privacy rules.