He was convicted of murder. IF you didn’t know, in the US, that renders anyone UNABLE to purchase firearms, barring an act of god on the presidential level.
There are only two places this man could have gotten them
1. He stole them
2. He bought them from the black market.
parallel between guns and drugs.
What have the laws against drugs done?
The same will happen with guns, if continued control measures keep piling up
All laws and control measures do, catpaw, is keep the honest person from doing it, not the criminals.