DELMAS, South Africa  Eudy Simelane was a 31-year-old lesbian activist and one of this nation’s best female soccer players, a tall, muscular woman who knew how to defend herself with her fists and her elbows. She could not have been easy to kill.

Before leaving her naked body face down in a drainage ditch, her murderers stabbed her nine times, said the doctor who performed the autopsy. Three of the deep cuts were in the upper inside of her thighs. Those wounds as well as the bruising at the entrance of her vagina led the doctor to conclude that the assailants had tried to rape her.

In February, one of the attackers, Thato Mpithi, 23, pleaded guilty to murder, implicating three other men before denying their involvement almost six months later. On Tuesday, in a courtroom here in Delmas, two of the men he named were acquitted for lack of evidence, though the judge, Ratha Mokgoathleng, warned that they might someday have to answer to God.

The other man on trial, Themba Mvubu, 24, had no reasonable explanation for his trousers’ being stained with Ms. Simelane’s blood. He received a life sentence but walked from the courtroom smiling, showing no contrition and telling a reporter, “Ach, I’m not sorry at all.” He disappeared down a stairway to a holding cell as some of Ms. Simelane’s friends shouted that they would prefer he be sliced into pieces.