HARBIN, May 6 -- Local police in northeast China's Heilongjiang Province have solved a murder-suicide case involving a family of four, they said Thursday.

The family was found dead in their house in Daoli District of Harbin City on Monday evening.

The investigation found the suspect, surnamed Zhao, allegedly killed his second wife, her parents, and her daughter from the ex-husband with a knife on May 1, according to the city's public security bureau.

Zhao fled the scene and hung himself later in Shangzhi City.

Police said Zhao had been in an escalating conflict with his wife before the murder.