Video footage and pictures that appear to show a man in Shanxi province beating his wife to death as onlookers stood by and did nothing have sparked outrage on the mainland and raised new questions about domestic violence.
Pictures of the assault first appeared on social media and in domestic news outlets on Sunday and have been shared millions of times.
State media said the violence erupted after the married couple accidentally hit a vehicle while driving an electric scooter in Shuozhou city. Police said in a statement the woman was killed on Saturday morning.
"The suspect is in the custody of public security organs, and the case is being fully investigated," police said.
In the footage, cyclists, motorists and pedestrians, including children, can be seen watching the street-side attack.
Media posts about the incident drew tens of thousands of comments, with most criticising the inaction of the bystanders and the lax attitude towards domestic violence in some sectors of Chinese society.
"He's not holding a machine gun, why did no one step forward to control him?" asked one commenter in a widely shared response.
The mainland only introduced a specific law criminalising domestic violence in 2015. Activists say violence within families is often ignored.
At the time the law was passed, the government-run All-China Women's Federation estimated that about one in four Chinese women experienced violence during their marriage. Authorities register some 40,000 to 50,000 complaints a year.
The outrage sparked by the attack is reminiscent of a 2011 incident, also caught on video, when a toddler in Foshan was struck by a vehicle twice and ignored by dozens of passersby.
Social media users pointed out that there is a widely held perception in China that someone who steps in to help could be liable for hospital costs, or ensnared in scams, discouraging people from intervening.
The mainland in 2017 enacted "Good Samaritan" legislation that aimed to tackle the issue by removing civil liability for those involved in helping victims of violence or accidents. (Reuters)