Fifteen or 20 minutes into the second half, Cantanhede ejected a player named Josemir Santos Abreu, 30, a friend and sometimes teammate who in an instant became an enemy. A yellow-card warning escalated into a red-card send-off, an argument, a lethal fight. Cantanhede twice stabbed Abreu, who died by the time he reached the nearby hospital. In retaliation, the police said, Cantanhede was set upon by at least four of Abreu’s friends, whose bleakest impulses were fueled by alcohol, drugs and a crowd that stoked the violence the way wind stokes a fire. Cantanhede was tied up, smashed in the face with a bottle of cheap sugarcane liquor, pummeled with a wooden stake, run over by a motorcycle and stabbed in the throat, the police said. The moment of death remained uncertain. What came before did not stop another of the accused from a gruesome completion.

