Well on the Ben Ferguson radio show he received text messages from LE he knows in Texas. Again, you guessed it, the suspect was already known to authorities as he had previous run-ins with the police.
So, this being the case, was he ever convicted of any type of felony or was he found of unfit mind? If either was the case then he was not eligible to own a firearm.
It may be a case of a minor whose record was expunged when he turned 18, never having done anything other than petty crimes.