Most victims were shot with a .22 sporting rifle and stabbed or bludgeoned with a wide variety of weapons ranging from stitching awls to bricks and iron bars.
On June 18, 1996, a 44-year-old factory worker named Yevheniy Osechkin was found dead near the Karavaevi Dachi railway station in Kyiv.
However forensics uncovered that the victim was actually shot with a .22 round (a single shell casing was recovered), and stabbed multiple times.
Two weeks later a well-known local doctor named Oleksandr Yehorov was shot and killed in his car in broad daylight.
Less than an hour after Yehorov's murder, another male victim was found several blocks away, again shot with a .22 rifle and stabbed.
On September 28 at about 10:30 PM, another male victim aged 35 to 40, this time a man named Petr Gromov, was found shot in his vehicle, a VAZ-2106.
Canvassing apartments near the Hromov murder scene, they located a woman who claimed to recognize one of the suspects as a man named Volodymyr who lived nearby.
Surveillance located an unlocked door in the building, and there was a dead body inside the apartment, also shot and stabbed.
Continued surveillance on a Sotzialistychna Street block where the Bykov and Gromov murders took place quickly located Kondratenko loitering with another man who also matched a suspect's description.
By the time the information was sent up the chain and the two men were ordered detained, the pair claimed one final victim, an unidentified woman they struck and killed while driving drunk at a high speed in a stolen VAZ-2102.
The car was stolen in preparation for a burglary of a commercial warehouse, where they also planned to murder the lone guard.
Serhiy Tretiachenko, a delivery driver, was charged with assisting Kondratenko with attempted auto theft in a murder/burglary scheme that was cut short by the arrest.
Tymoshyn also changed his testimony, claiming that he was unaware that the other men planned to kill their victim, and simply went along to rob a taxi driver.
Kondratenko had earlier stated that Tymoshyn had offered them a price to kill that particular victim, who was apparently in conflict with the inspector.
[1][2][3] According to a psychological profile prepared by the prosecution, Kondratenko had been a model child until he started school, when constant physical abuse by his father began to take its toll.
Army service was reportedly hard on Kondratenko, who was frequently injured, once receiving a serious concussion after falling from a tank.
He was discharged after the compulsory service, and reported back home in civilian clothes, instantly inviting a beating from his father for not being in uniform.
Kondratenko planned to go back to school, but came down with a severe case of jaundice which left permanent disfiguring marks on his face.
Growing up in poverty, Volkovich was always preoccupied with appearances and looking for ways to make money, but did not want a full-time job.
He made friends with Kondratenko and the two men often discussed various ways of making money, as well as various philosophical concepts, eventually deciding that "there is no such thing as morals or honor in this world".
They eventually settled on attacking car owners; owning a personal vehicle was a considerable luxury and a sign of wealth in the former Soviet Union of the early 1990s.