Ou was sent to hospital and died despite emergency rescue efforts, the police statement added.
Over the past week, hundreds of police and other search crew members had been looking for Ou in the hills, where he fled after allegedly attacking his neighbors in a seaside village in Putian on Thursday.
Police and paramilitary forces eventually found him in a cave on Monday afternoon and rounded him up, according to the police statement.
Police said Ou, 55, attacked his neighbors with a knife amid a long-running land dispute, killing a 78-year-old man and his daughter-in-law. The man’s wife, 34-year-old grandson and 9-year-old great grandson were also injured.
The manhunt gripped millions in China, many of whom openly hoped he would never be caught. The level of sympathy and support is highly unusual for an alleged killer in China, where murder is punishable by death.
In the absence of initial official information, Chinese media and the public used accounts of fellow villagers, Ou’s past social media posts, and previous media reports to piece together an unofficial version of events that could have led to the killings.
Many believed Ou was an ordinary man pushed to the brink of despair over a years-long housing dispute. Public sympathy surged further after reports emerged that he had saved a young boy from drowning at sea three decades ago and rescued two dolphins that were nearly stranded in 2008.
For nearly five years, Ou and his family — including his 89-year-old mother — did not have a home, according to Ou’s Weibo posts and Chinese media reports. Instead, they lived in a tiny tin shack in a seaside village in Putian city.
According to the posts, Ou was repeatedly prevented from building his own house due to land disputes with his neighbor. He said he sought help time and again from police, village officials, the government and the media, but the problem remained unresolved.
A village official told state-run newspaper the Beijing News that local cadres had tried to mediate, to no avail.
Many blamed Ou’s apparent transition from savior to murder suspect on the ills that have long plagued China’s local governance, from abuse of power to official inaction. Others see it as a reflection of the broader failure of the country’s legal and bureaucratic system, exacerbated by a besieged free press and a crippled civil society.
As the murders gained public attention, Ou’s account on microblogging site Weibo vanished, and the local government of Pinghai county issued a bounty for Ou, offering a higher amount of cash rewards for proof of his dead body than any information leading to his arrest — triggering further public outrage.
And on Monday evening, many were saddened by news of Ou’s death.
Others were said they were not convinced that Ou took his own life, and called for the police to release videos of the arrest (police in China are often required to record arrests and other law-enforcement activities with body-worn video cameras.)
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