THE decapitated bodies of a Ukrainian judge, who was an internationally known antiques collector, and his wife, son and son's girlfriend were found in his apartment in the city of Kharkiv at the weekend.
Interior Minister Vitaly Zakharchenko said several antiques appeared to be missing from the home of Volodymyr Trofimov, 58, who had a collection of rare coins, military medals and china statuettes.
An Interior Ministry statement said "all versions (being looked into by investigators) are based on the same conclusion: this crime was carefully planned and thought out in advance."
Quoting state prosecutors, Ukrainian newspaper Segodnya said Trofimov's cases as a district court judge in recent years were limited to alimony payments, petty theft and debt collections.
The lock on the door of Trofimov's flat, located in a Soviet-era apartment block, was intact, according to the newspaper. Investigators have yet to find the heads of the dead, whose bodies were found on Saturday.
Ukraine, a former Soviet republic, had a murder rate of 5.2 per 100,000 population in 2010, compared to 10.2 in Russia and 1.1 in Poland, according to the UN Office on Drugs and Crime.
However, execution-style murders like that of the judge are rare and senior law enforcers, including the prosecutor general and Interior Ministry and security service SBU officials, flew to Kharkiv at the weekend to coordinate the investigation.
The most infamous decapitation case in Ukraine was the 2000 murder of investigative reporter and editor Georgiy Gongadze, whose body was found in a forest soon after he was abducted.
Several police officers have been convicted for the murder and Yuri Kravchenko, interior minister at the time, was found dead in his country home in 2005. He had been shot in the head twice in what the authorities ruled was a suicide.
A murder charge against Leonid Kuchma, Ukraine's president from 1994 to 2005 and the main target of Gongadze's critical reports, was thrown out by a local court last year.