But witnesses said the car sped off and Zeng was dragged and then thrown from the SUV, fatally striking his head against a parked car.
"He was bleeding only from the head. His face was purple and blue," Maria Chan, who runs a flower shop across the street, told ABC News.
Witnesses said three masked men were involved in the robbery. Police arrested two suspects in what they described as a homicide investigation.
Zeng was a Chinese native who attended Kansas State University for graduate school, according to CNN. He moved to the Bay Area in 2015 to work as a research scientist and engineer for IBM company Aspera.
After receiving the devastating news, his parents traveled from China to formally identify their son's body and arrange for his funeral.
Zeng's Facebook page reveals he was an avid photographer and hiker; his cousin told ABC he likely tried to save his laptop to either preserve all of his research or the photos he was editing from their recent vacation together.
"I still can not believe that this happened," she said. "I do not want him to be remembered as a victim of a robbery because he's so much more than that. He's a scholar, he constantly reads."
His friends discovered he was dead after receing a call from police as they gathered at his apartment for a joint birthday party / New Year's Eve celebration.