Kaspars Petrovs, born in 1978 in Grobiņa, Latvia, is the son of a prominent medical doctor. Despite his family's status, Petrovs experienced homelessness for several years. Prior to his arrest in 2003, he had a prior conviction for theft in 1998.

Between 2000 and 2003, Petrovs targeted elderly women in Riga, Latvia. He would follow his victims home, forcibly enter their residences, or pose as an employee of Latvijas Gāze, the state gas company, to gain entry. Once inside, he strangled the women and subsequently stole money and goods, totaling approximately 18,000 lats (26,000 euros). ​

Initially detained in connection with five murders in February 2003, Petrovs confessed to over thirty killings. However, due to insufficient forensic evidence, authorities pursued charges in 13 cases. On May 12, 2005, the Riga Regional Court convicted Petrovs of 13 murders, eight attempted murders, and multiple thefts and robberies, sentencing him to life imprisonment. ​

During his trial, Petrovs claimed he did not intend to kill his victims but only to rob them. He apologized to the victims' families in court, expressing regret for his actions and acknowledging that his words could not bring back the deceased.