Kyriakos Papachronis was born in 1960 in Xanthi, Greece. His parents were Erifili and Charalambos Papachronis. He had one brother and one sister. The family owned a cafeteria in the city, and Kyriakos worked there from a young age.

After finishing high school, he moved to Athens for a short time. In Athens, he worked in various hotels to support himself. Kyriakos was very interested in sports. He excelled in boxing and karate. He became a champion in both sports, particularly in boxing, where he was declared champion in the 90 kg weight class.

On September 9, 1981, Kyriakos Papachronis visited a brothel in Xanthi. He requested the services of a 46-year-old prostitute. After an argument broke out, he returned later that day and stabbed her to death.

Papachronis targeted more women after that. On December 20, 1981, he attacked another prostitute in Drama. He followed her and stabbed her in the back, but she screamed, and he fled the scene. Just ten days later, on December 30, he attacked a 19-year-old student after she left a movie. He stabbed her in the cervix, but her father saw the attack and Papachronis ran away.

On January 15, 1982, he attacked a nurse near a train station in Drama. He tried to rape her but left her alive. She later provided the police with a detailed description of him. On August 15, 1982, he met a girl named Anastasia Alexandridou at the Archaeological Museum of Thessaloniki. He followed her home, forced her into a grove, and stabbed and raped her. He took her belongings but kept her lighter, which later linked him to her murder.

In the following months, he attacked more women. On September 21, he tried to kill a 23-year-old, but she escaped. He seriously injured an 18-year-old outside her home on October 1 and a 32-year-old prostitute in Xanthi on October 25. His final victim was a 30-year-old mother of four whom he stalked before attacking her on December 30, 1982. He stabbed her in the face and neck and then disappeared.

The police collected descriptions from survivors that identified him as a man in military uniform. This helped narrow down the suspects. Military officers noticed that Papachronis had been unaccounted for during crucial times. They searched his home after he displayed nervous behavior during questioning. They found knives and the lighter he had kept from Anastasia. He was arrested on December 13, 1982.

Initially, Papachronis denied his involvement. However, inconsistencies in his statements and identifications from survivors led him to confess to the crimes. He also admitted to planting bombs in various places during that period.

His trial took place from June 14 to June 18, 1983. It drew significant media attention. Papachronis arrived in court displaying aggressive behavior, claiming to be a brave man. He was charged with multiple murders and other violent acts. Despite attempts by his lawyers to seek leniency based on his young age, the court sentenced him to death for two murders and additional time for other charges.

Papachronis began serving his sentence at a prison in Corfu. His behavior was unruly and aggressive during his early years in prison. Over time, he became calmer and began pursuing various activities, including studying theology and psychology. He maintained correspondence with women who were interested in him, often called "serial killer groupies."

After serving 22 years, he was released on parole on December 8, 2004. In his statement to the press, he reflected on his past and expressed a desire to live quietly.