SPOILER SPACE
and all that jazz
Yep, the "Red Brigade" is the criminal gang that won't go away...
The facts depicted are fictional, but the screeplayers (and the book's author before them) did a fine job in throwing those facts over a real-life backdrop. Brazil's version of Gangs of New York, y'know?
If you liked that, keep your eyes peeled for the next major release, Carandiru, which depicts a doctor's daily life as a voluntary at a huge brazilian prison where 111 inmates were killed by the police during a riot some 10 years ago. The prison has since been imploded.