SACRAMENTO (CBS13) — A South Sacramento gun shop has been shut down after federal authorities arrested the owners for allegedly making homemade assault rifles.

It’s all chained up now after the federal raid, but federal agents say the machine shop was one of many places people could go to get illegal and untraceable guns.

Federal authorities say undercover photos of brothers Luis Cortez Garcia and Emiliano prove they were illegally manufacturing assault rifles in Sacramento.

“Undercover agents purchased numerous completed firearms from each of the defendants,” said U.S. Attorney Benjamin Wagner.

He laid out part of the case against the brothers and others, saying the siblings ran a so-called machine shop in South Sacramento, with the help of other locations—places where customers could buy parts of a gun, and then have them assembled.

“Sold without any firearms transaction records, without any background check, without any waiting period,” Wagner said.

He says the brothers were likely trying to skirt the law in the United States. It’s legal to make your own gun, but selling a homemade gun to someone else is a federal offense.

Just Guns owner John Deaser says they’re required to register every gun sold, and illegal sales often mean guns end up in the wrong hands.

“Somebody who is not a law-abiding citizen, it gives them an out to get their hands on something they shouldn’t have their hands on either,” he said.

As the investigation continues, authorities say they are almost positive more arrests will be made on top of the brothers who now face numerous federal weapons charges.