Ok, here is how I know the entire article is bullshit. When they say 3D printed, they really mean that some parts like the trigger or the stock are 3D printed. The actual weapon still relies on steel barrels and other steel components. The 3D printed portion is often entirely insignificant and sometimes only two weapons out of half a dozen were 3d printed but the articles make it sound like all of them were and that 3D printing was the primary factor.

The article mentions this [0] synagogue shooting in Germany.

>En octubre de 2019, en Alemania, se cometió un atentado terrorista contra una sinagoga judía, en el que otras armas y explosivos, se utlizó un fusil fabricado con una impresora 3D.

Google translate: >In October 2019, in Germany, a terrorist attack was committed against a Jewish synagogue, in which other weapons and explosives, a rifle manufactured with a 3D printer was used.

The shooter didn't need to 3D printing at all, all of his weapons (he had a complete arsenal ranging from handguns to shotguns to rifles) were made primarily made out of steel. The reason why he couldn't get through the synagogue door is that he couldn't obtain ammunition so he had to use a weak gunpowder substitute to make his own. I consider this proof that strict gun laws prevented this shooting from occurring the way he wanted.

Images of the non 3d printed guns:

https://img.huffingtonpost.com/asset/5da09aee200000690550003...

https://pbs.twimg.com/media/EGdwR-hWsAERlKN?format=jpg&name=...

https://i.redd.it/q6qhms9a0pr31.jpg

Images of his partly 3d printed guns:

https://preview.redd.it/hp9ot6apeqa51.jpg?width=960&crop=sma...

https://d3pbdxdl8c65wb.cloudfront.net/cloudinary/2019/Oct/10...

I'm more worried about the ones with wooden stocks, than the 3d printed ones, primarily because he didn't even use them.

[0] https://en.wikipedia.org/wiki/Halle_synagogue_shooting