Created in 2004, the National Force is composed, according to the Ministry of Justice, of the “best police officers and firefighters from the elite groups of the states.” They undergo a “rigorous training” at the National Police Academy, which covers everything from crisis specialization to human rights.
To obtain support from the National Force, the state governor must make a request to the Minister of Justice and Public Security. If the minister authorizes it, the force is dispatched to the municipality to support the Military Police, the Civil Police, the Fire Department, or the official Forensic Examination bodies.
It is also possible for the force to support operations of agencies 
such as the Federal Police, the Federal Highway Police, or the Brazilian Institute of Environment and Renewable Natural Resources (Ibama) or ministries and federal agencies. One example is the confrontation of environmental crimes in the Amazon.
To participate in the National Force, military personnel go through a selection process and must meet several prerequisites. They must be between 25 and 40 years old, with at least five years of professional experience. They must also be available for summons for a period of 90 days, on an undetermined date, and have received a “very good” rating on the physical fitness test.
More than 11,000 police officers have already undergone the two-week training to join the National Force. During this period, they face a rigorous routine of exercises and a course of ten subjects, including Human Rights, Civil Disturbance Control, Overt Policing, Crisis Management, and Shooting Techniques. The agents simulate chases and approaches to suspects.
Source: Government of Brazil