A fire investigation aims, in the broad concept, to raise and point out aspects and circumstances related to a fire. In fact, as a task that involves scientific knowledge and techniques, it must be planned and carried out with tested and valid protocols. There are some fire investigation protocols that contribute a lot to the evaluation of the fire scene, but they are usually limited to the fire scene and do not address the fire investigation as a whole, comprehensive and holistic way. The lack or insufficiency of protocols can lead to inadequate fire investigations, which may be missing relevant data, present incipient results, with biased conclusions, and may jeopardize parties involved in a fire. So, it is vital the application of attested protocols and methodologies that ensure a global, integral, and holistic fire investigation, which expose – as much as possible – the facts, circumstances, factors, actions, omissions, and contributions related to the fire incident. In addition, a guided conduct of a fire investigation team, illustrated in a fire investigation protocol, must seek to provide information, foster, and improve fire safety science, at local to global scale. The present paper proposes a fire investigation protocol, involving connected methodologies, focusing on not only in fire investigation itself, but addressing a global context of promoting fire safety.