LOS ANGELES (AP) -- The University of California Los Angeles, where an investigation into the use of a Taser gun against a student is under way, appears to be the only UC campus that allows officers to stun noncombative suspects as well as those putting up a fight.

Police at six of the 10 UC campuses carry Taser guns. Most are restricted to only using the guns against violent suspects, according to interviews with top UC law enforcement officials.

UCLA's police rules, however, allow officers to use Tasers on passive resisters as "a pain compliance technique," Assistant Chief Jeff Young said last week.

Officers can use the weapons after considering the potential injury to police and to the suspect, as well as the level of the suspect's resistance and the need for prompt resolution, he said.

Taser use was put into the spotlight after UCLA senior Mostafa Tabatabainejad, 23, was repeatedly stunned Nov. 14 when he refused to show his student ID to officers doing a late night check at Powell Library, according to authorities. Tabatabainejad said through his lawyer he didn't want to produce his ID because he thought he was being singled out because of his Middle Eastern appearance.

Video footage of the incident posted on the Internet showed Tabatabainejad screaming and writhing on the computer lab floor. The stun guns are made by Scottsdale-based Taser International.

In interviews with the Los Angeles Times, police officials at UC San Diego, Riverside, Irvine and Merced said officers only use the weapons against suspects who pose a physical risk. They did not comment specifically on the UCLA incident.

"It can only be used when it appears reasonable under the circumstances to restrain or arrest a violent or threatening suspect," said UC Riverside Police Chief Michael Lane.

Taser use is "authorized when facing a violent or potentially violent individual," said UC Irvine Police Chief Paul Henisey.

Police Chief Rita Spaur of UC Merced said officers would not deploy a Taser unless "it was the last means to protect themselves" or other people.

UCLA police bought 16 Taser stun guns two years ago, said Nancy Greenstein, UCLA's director of police community services.

Police at UC campuses in Berkeley, Santa Cruz, San Francisco and Santa Barbara are not equipped with Tasers.