Three Maryland high school students were charged after gaining access to a teacher's online grade book, Baltimore station WBAL is reporting.

Charging documents said Kenneth Van Dyke, 18, admitted to police that he's changed his grades in multiple classes since October 2006.

Two other students also had their grades changed by the suspect, according to investigators.

Sgt. Michael Holmes of the Cecil County Bureau of Investigations said his office was contacted last month after an algebra teacher noticed that a one-time failing student was passing her class.

"We consider this a very serious matter," said Superintendent Henry Schaffer. "Student performance is paramount to us. Basically, this was cheating and this will not be tolerated.

"The students in question have been dealt with in a matter that we feel is appropriate, including referral to law enforcement."

Van Dyke was charged with one count of illegal computer access. The other two students were charged with conspiracy to commit illegal access.

The offenses are punishable by up to three years in prison and a $1,000 fine.