"Most people agree that the hit-to-kill phenomenon stems at least in part from perverse laws on victim compensation. In China the compensation for killing a victim in a traffic accident is relatively small—amounts typically range from $30,000 to $50,000—and once payment is made, the matter is over. By contrast, paying for lifetime care for a disabled survivor can run into the millions. The Chinese press recently described how one disabled man received about $400,000 for the first 23 years of his care. Drivers who decide to hit-and-kill do so because killing is far more economical. Indeed, Zhao Xiao Cheng—the man caught on a security camera video driving over a grandmother five times—ended up paying only about $70,000 in compensation.
http://www.slate.com/articles/news_and_ ... a_s.2.html
Security cameras have regularly captured drivers driving back and forth on top of victims to make sure that they are dead.
In 2010 in Xinyi, video captured a wealthy young man reversing his BMW X6 out of a parking spot. He hits a 3-year-old boy, knocking the child to the ground and rolling over his skull. The driver then shifts his BMW into drive and crushes the child again. Remarkably, the driver then gets out of the BMW, puts the vehicle in reverse, and guides it with his hand as he walks the vehicle backward over the boy’s crumpled body. The man’s foot is so close to the toddler’s head that, if alive, the boy could have reached out and touched him. The driver then puts the BMW in drive again, running over the boy one last time as he drives away."

Here too, the driver was charged only with accidentally causing a person’s death. (He claimed to have confused the boy with a cardboard box or trash bag.) Police rejected charges of murder and even of fleeing the scene of the crime, ignoring the fact that the driver ran over the boy’s head as he sped away." Perhaps the most horrific of these hit-to-kill cases are the ones in which the initial collision didn’t injure the victim seriously, and yet the driver came back and killed the victim anyway. In Sichuan province, an enormous, dirt-encrusted truck knocked down a 2-year-old boy. The toddler was only dazed by the initial blow, and immediately climbed to his feet. Eyewitnesses said that the boy went to fetch his umbrella, which had been thrown across the street by the impact, when the truck reversed and crushed him, this time killing him.
Despite the eyewitness testimony, the county chief of police declared that the truck had never reversed, never hit the boy a second time, and that the wheels never rolled over the child. Meanwhile, one outraged website posted photographs appearing to show the child’s body under the truck’s front wheel"