He was already dead when police arrived at the scene, said Shen Qian, a press officer with Changning district police. Officers detained Liu for questioning.
Liu did not speak to Tao when he approached the van, according to the website's report, so it remains unclear whether he was aware of the taxi driver's presence.
The distinction will be important if Liu is charged in the case, according to Li Fei, a lawyer who specializes in traffic law at the Shanghai Push Law Firm.
Liu could be charged with involuntary manslaughter or voluntary manslaughter, depending on whether he was aware of the possibility that he could cause Tao harm when he drove away, Li told the Global Times.
Police said the case remains under investigation.
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