The shocking footage shows one officer hitting a Vietnamese student Phuong Ho with a metal baton more than 10 times, including once over the head.
Another officer is seen striking the 20-year-old San Jose State Mathematics student with a Taser gun, in the video posted on the San Jose Mercury News website yesterday.
The final baton strike in last month's incident appears to take place after handcuffs have been attached to Ho's wrists.
The sickening footage has prompted calls for a criminal investigation into the officers' conduct, a San Jose police spokesman said.
Watch the video here
The video, made by one of the student's roommates without the knowledge of police, shows that force was used even though the suspect was on the ground, and apparently offering no physical threat to the officers. Several experts in police force said the video appears to document excessive — and possibly illegal — force by the officers. A police spokesman Friday said the department had opened a criminal investigation of the office conduct, after police officials viewed a copy of the recording.