Los Angeles  - It sounds like the kind of prank that any devious and mildly criminal high school student might undertake.

But Omar Khan's attempt to hack into the computers at his southern California high school to change his grades to A could land him with as much as 38 years in jail after he was charged with 69 felonies, according to the Orange Country Sheriff's Department.

In their arraignment on Thursday, County prosecutors alleged that Omar Khan, 18, of Coto de Caza, California, and Tanvir Singh, 18, broke into Tesoro High School in Las Flores to steal tests and change their own and others' grades on the school computer network.

Singh is alleged to have tried the scam only and faces four counts that could land him in jail for three years, while Khan apparently did it repeatedly.

Khan was arrested Monday and released on 50,000 dollar bail, while Singh was released on his own recognizance.

The charges against Khan include altering and stealing public records, computer fraud, burglary, identify theft and receiving stolen property and conspiracy, Orange County district attorney spokeswoman Susan Schroeder said.

He is alleged to have used a stolen master key to break into the school, and log on to an administrative computer using pilfered access codes to alter his C and D grades to As and thus improve his chances of being admitted to the one of the campuses of the elite University of California system.

Prosecutors say Khan also installed software that would allow him to access the school network remotely, though there was no allegation he ever did do so.

Suspicions about Khan were raised in April after he was rejected by the university and then appealed after he changed his grades.

"Khan was known as a student with average grades. Then all of a sudden, school officials saw that he had a lot of As. That was a red flag," Sheriff's Department spokesman Jim Amormino told the Orange County Register. (dpa)