For 100 days we collected 137 bullet shells in twenty-seven neighborhoods of the metropolitan region of Rio de Janeiro, immediately after the gun fights, between police officers, drug dealers or militiamen. After the collection, we split the material according to place, date, and agent involved in the conflict. With all this information ready, the material was repassed to the “Instituto Sou da Paz” and to the Small Arms Survey. They identified the manufacturer, caliber, batch and the year of production of the ammunition. We have searched on the press and in the database of the platform “Fogo Cruzado” – that maps shootings and shootouts – all the information referring to the current events of the day to understand who was Involved in these conflicts and the similarity between the material used by them. Thereby, we could put in a map the history of these bullet shells – that travelled thousands of kilometers – until they were fired on the favelas of Rio de Janeiro. We analyzed the actual legislation to understand where are all the gaps – especially to the Brazilian production – and we identified a huge fragility in the inspection done by the army and an absolute lack of transparency from Taurus.