1. Adam Lanza created Youtube account called "Trolleyrulle" on December 12th 2012. We know this account was created on December 12th 2012 as it says.

2. Adam Lanza uploaded the video on December 13th 2012.

3. Adam Lanza carried out shootings on December 14th 2012.

Its obvious!

You CANNOT change the name of an original Youtube account. Unless I am mistaken?!?

That original Youtube account name is "Trolleyrulle".

"Trolleyrulle" was mention on the text over the video - so there is already that link.
Even if somebody did change and edit the text over the video THERE IS STILL THE LINK TO THE NAME OF THE YOUTUBE ACCOUNT CALLED "TROLLEYRULLE"

And nobody can possibly change the Youtube accounts name, right??

This Youtube account was created just TWO days before the shootings took place!