He was convicted of the murder of thirteen elderly women by the Riga Regional Court on 12 May 2005 and sentenced to life in prison.
However, authorities only pursued charges in the deaths of 13 of the victims due to a lack of forensic evidence in the other cases.
Petrovs, who had a previous conviction for theft in 1998, maintained after his arrest and during his 2005 trial that he had not "intended to kill his victims, but only to rob them".
[1] Petrovs strangled the women after following them home and forcibly entering their apartments or posing as a Latvijas gāze (state gas company) employee.
Petrovs stole an estimated 18,000 lats (26,000 euros) in goods and money from his victims.