- "Don't be afraid of the fires. You think they'll hurt ya. You think they'll char your skin and char your bones, but it'll make you clean in the long run."
It appears that Brewer was part of the 5th Platoon, presumably in Vietnam. This can be seen on the jacket he wears that covers up the bomb. He may have lost his sanity from the things he saw, resulting in him killing himself many years later, to rid him of his troubles.
The conspiracy theories and Brewer's nonsensical way of talking indicates he suffers from some sort of mental illness, possibly schizophrenia. Brewer seems to jobless, and could only be squatting in the small apartment he lives in, or at Walton's Bar.
After Max kills the son of Anthony DeMarco, he is hunted by a large group of gangsters. While Max is escaping his apartment complex, a gangster catches him at gunpoint. Brewer comes out of his apartment and shoots the man, then turns to Max and tells him not be afraid of fire. He says that although it will burn him, it will cleanse him in the long run. Wires are visible on his chest, and he approaches three gangsters, detonating a bomb. This kills all four of them.
Max investigates Brewer's apartment, which is filthy and messy. Taped to a wall are examinable newspaper clippings detailing Max's fall from grace as a police officer, and conspiracy theories are written on another wall in black marker. A manifesto sits on a table with more bombs and tools. This indicates that Brewer had other plans with his explosives before Anthony DeMarco and his men showed up.
Max regrets Brewer's death, and attempts to justify it to himself by saying that Brewer was waiting for an opportunity to make a difference and wished to get to know a little bit more about Brewer.
- Brewer appears to have post-traumatic stress disorder, proving some symptoms by how he believes he can cleanse himself of his sins by blowing himself up along with others.