Sipho Mandla Agmatir Thwala was born in 1968 in KwaMashu, a township near Durban, South Africa. He grew up in a rural environment and faced a challenging upbringing. Thwala never knew his biological father, and his stepfather abandoned the family during his early years. His mother, Khathazile Ntanzi, was the dominant figure in his life, but their relationship lacked warmth. Thwala attended school but did not complete his education, dropping out during the elementary years. He was known to take on various short-term jobs but struggled to maintain steady employment. Described as intelligent yet introverted, Thwala was fluent in English, Afrikaans, and Zulu. A significant personal setback occurred when his partner terminated a pregnancy without his knowledge, leading to deep-seated resentment towards women.

Between 1996 and 1997, Sipho Thwala embarked on a series of heinous crimes in the KwaZulu-Natal province of South Africa. He would lure women into the sugarcane fields near the town of Phoenix, promising them employment as domestic workers in local hotels. Once secluded within the fields, Thwala would bind his victims using their own undergarments, sexually assault them, and then strangle them to death. In an attempt to destroy evidence, he would set the sugarcane fields ablaze, a common agricultural practice that he exploited to his advantage.

The investigation faced challenges due to the destruction of evidence from the fires. However, a breakthrough occurred when a body was discovered before the field was burned, allowing authorities to collect crucial DNA evidence. In 1997, police matched DNA found on the victims to a sample taken from Thwala in 1994, when he had been arrested and later acquitted of a rape charge. This match led to his arrest on August 14, 1997.

His trial was held at the High Court in Durban. On March 31, 1999, Thwala was convicted of all counts and sentenced to 506 years in prison. His sentencing included multiple life terms and additional years for rape and related charges, reflecting the severity and sustained brutality of his crimes. The media dubbed him “The Phoenix Strangler,” a moniker referencing both the location of his crimes and the methodical manner in which he stalked and eliminated his victims. He is currently serving his sentence at C-Max Penitentiary in Pretoria, South Africa. ​