Although it was originally intended for military use, it was well-suited for law enforcement and ended up being marketed to bodyguards, VIP protection and special operations units.

This allowed for the importation of German weapons manufacturing machinery and technical know-how, which stimulated development of new firearms designs in Portugal.

The bolt and carrier are one welded unit, and the action is a simple blowback, unlike the roller-delay system of the MP5.

The Lusa fires from the closed bolt position in both semi- and fully automatic modes.

In 2004, INDEP sold all the dies, tooling, fixtures and manufacturing rights to Stan Andrewski, owner of Stan's Gunsmithing in New Hampshire, Jerry Prasser, owner of Recon Ordnance in Wisconsin, and Ralph Dimicco, co-owner of Riley's Gun Shop.

The LUSA was approved for sale as a semi-automatic by the BATFE (Bureau of Alcohol, Tobacco, Firearms, and Explosives) for the US civilian market.

As of 2006, LUSA USA planned to offer conversion kits in .22 Long Rifle, .40 S&W and .45 GAP but distribution of these never materialized.