Four Northern California police officers who were present during the violent videotaped arrest of an unarmed college student will not face criminal charges, prosecutors said Wednesday.

Santa Clara County District Attorney Dolores Carr said there was insufficient evidence to prosecute the officers on charges they used excessive force when trying to arrest Phuong Ho, a Vietnamese student at California State University, San Jose.

The Sept. 3 arrest has angered the San Jose's large Vietnamese-American community, which was already upset over the fatal police shooting of a mentally ill Vietnamese man in May.

The incident began when police received a 911 call that a man was out of control and waving a knife at his roommate. Carr said when officers arrived at the home, Ho was uncooperative and unwilling to follow orders, and when officers tried to restrain Ho, he twisted away.

Carr noted that Ho's actions may have been a result of miscommunication with the officers about whether they had permission to go into his room.

"Nevertheless, at that point, the situation changed from an investigation by police of a man who had threatened violence against his roommates to an increasingly unsuccessful attempt by police to gain control over a physically resistant subject," Carr said.

She said one officer used a "control hold" to get Ho to the ground but he repeatedly refused to comply with orders to turn over to be handcuffed.

"Force was used intermittently for the purpose of gaining his compliance," Carr said.

Much of the incident was caught on cell phone video taken by one of Ho's roommates. The grainy recording shows one of the officers striking Ho repeatedly with a baton and another officer using a stun gun to try to subdue him. Two other officers are at the scene later to try to help handcuff Ho, but did not use weapons.

"A jury hearing criminal charges against these officers would likely conclude that the force used here — 13 baton strikes in 45 seconds — was reasonable under the circumstances," Carr said.

She said the use of the Taser also did not appear to affect Ho. The Taser was used in "drive stun mode," which is intended to cause some pain but does not shoot darts that incapacitate the target or affect the central nervous system, she said.

Ho later told police he didn't feel any pain from the Taser, but instead felt energized like he had been drinking a Red Bull, Carr said.

Carr acknowledged that the video was very disturbing but two of the three experts who reviewed the footage for her office — all former police officers — agreed that the officers acted reasonably under the circumstances. She said the third expert believed the officers used excessive force in the situation and should have been able to subdue Ho without numerous strikes by a baton.

"This wasn't about whether we agreed with the officers," Supervising Deputy District Attorney Lane Liroff said. "It was whether we could persuade a jury."

Carr's office recently dismissed resisting arrest and other charges against Ho, also believing a jury would not likely convict the math major.

Ho, who is from Ho Chi Minh City, told the San Jose Mercury News on Wednesday he was just glad charges were dropped against him. The most important thing was being able to stay in the U.S. to study, he said.

Police internal affairs will now conduct their own investigation into Ho's arrest and decide whether the officers complied with department rules regarding force.