Chow Tsz-lok, who studied at the University of Science and Technology (UST), fell on Monday from the third to the second floor of a parking lot.
Protesters and police fought running battles on the streets of Hong Kong on Friday as a vigil for a student killed on Monday turned violent.
Students had gathered to pay their respects to Chow Tsz-lok, 22, who fell from the third to the second floor of a parking lot when protesters were being dispersed by police.
His fellow students at the University of Science and Technology (UST) smashed up a Starbucks outlet, writing "Condemn police brutality" on the restaurant's glass wall.
In Mong Kok, one of the most densely populated neighbourhoods in the world, demonstrators built barricades, attacked a metro station and destroyed a phone booth.
The protests in Hong Kong have been raging for months, ever since the authorities tried to implement a bill that would allow residents to be extradited to mainland China and has since been scrapped.