Admitting he’s an illegal would be an admission that this crime was completely preventable. So they simply go into default mode for when the shooter does not fit a Demographic they feel they can run with. Guns bad is a perfect fit for the narrative they want pushed so that's what they go with. Jessie Smollett would have a difficult time coming up with a good pretend story for the regime to use on this particular crime spree.
It wasn't the gun that killed these five innocent people, it was Bidens open border and every leftist who has turned a blind eye to the sieve that it has become. Yes, it was the serial invader who pulled the trigger on a gun he illegally possessed, but he had plenty of accomplices. To many of them, this case is a throwaway, it just doesn't check all the boxes they want and need to be checked.