A student at the University of California at Riverside was arrested on Friday after he allegedly hacked into the university's computer system during student-government elections and cast 800 votes for a fictitious candidate he called American Ninja.

Shawn Nematbakhsh, a senior and a computer-science major, was arrested on charges of altering computer data without permission and on investigation of drug possession. When police officers served a search warrant at Mr. Nematbakhsh's home they found marijuana and psychedelic mushrooms, according to the Associated Press.

Authorities said Mr. Nematbakhsh was working in a computer lab at the university in April when he discovered a programming flaw that allowed him to vote multiple times. He reportedly said he was trying to demonstrate the ease of breaking into the university's computer system. The elections were held again in May because of the tampering.

If he is convicted, Mr. Nematbakhsh faces a maximum of three years in prison and a $10,000 fine. He is currently free on bail and is scheduled to appear in court on Tuesday. He will also appear before a university judicial review board, which has the power to impose sanctions, including expulsion.

When reached at his home Sunday, Mr. Nematbakhsh declined to comment. A university spokesman did not return telephone calls on Sunday.

It is unclear why Mr. Nematbakhsh chose the name "American Ninja," which is also the title of a series of kung-fu movies released in the 1980s and early 1990s.