David Thabo Simelane was born in 1956 in Swaziland (now called Eswatini). Not much is known about his childhood or family life. As an adult, he had trouble with the law, including a conviction for theft. After being released from prison, Simelane reportedly became angry and resentful toward women, believing that some had falsely accused him.

Between the late 1990s and April 2001, David Thabo Simelane murdered at least 45 people, mostly women, in Eswatini. He tricked women by offering them jobs or help. Once alone with them, he attacked and strangled or stabbed them to death. Many victims were assaulted before being killed, and some were even decapitated. Simelane robbed his victims of their belongings after the murders.

The crimes were uncovered in April 2001, when police found several shallow graves in the forests near the Usuthu River. After discovering many bodies, the police arrested Simelane on April 25, 2001. He confessed to the murders and led police to additional bodies. In total, 45 victims, including women and four infants, were discovered.

After a long trial, Simelane was convicted of 28 murders and sentenced to death on April 1, 2011. He showed no remorse for his crimes. Although he appealed the sentence in November 2011, the death sentence was upheld. His crimes shocked the nation, and he remains on death row, making him one of the most notorious criminals in Eswatini's history.