Straw purchases are illegal and felons can’t posses firearms. Fathers can give firearms to sons, daughters, etc, but not if they are felons.
Unless you work for the BATFE.
The article I read said he had been arrested numerous times, said nothing about him being a convicted felon.
That is neither here nor there, considering his Dad or uncle that gave him the 45 for birthday gift had to have known he was taking psych drugs and had mental issues the giver holds some responsibility here.