Over the years, Corona del Mar High School has earned a reputation as one of the state's top public schools. Living in a seaside enclave of quaint old homes and cliff-top mansions, the school's students benefit from private tutors and their parents expect them to go on to elite universities.

But in recent weeks the school's sterling record has been shaken by an ugly cheating scandal. And, on Wednesday, 11 students were expelled.

School officials say that a tutor who worked with some of the students masterminded a scheme in which students obtained the passwords and log-on information of teachers and hacked into the district computer system to change grades and access exams.

Early Wednesday, after lengthy closed-door meetings, the Newport-Mesa Unified School District trustees announced their decision to take a hard line and adopt the most severe penalty under consideration.

"As a Board of Education, we are unanimous in our resolve to ensure the academic integrity ... as well as in delivering justice for the cases before us," said board President Karen Yelsey.

The students will be able to attend other high schools in the district, but the expulsions could be divulged to colleges if admissions officers asked why they changed schools.

Newport Beach police officers have been helping the district investigate the cheating since June, when a teacher notified administrators of the possibility that someone accessed her computer and altered grades, according to an affidavit.

By December, they had identified 12 students suspected of involvement in the alleged scheme and the private tutor, Timothy Lance Lai, 28. Officers searched his home the next day, but he had left and they have been unable to find him since.

Authorities said Lai instructed the students to attach a keylogger — an inconspicuous device that can monitor keystrokes — to various teachers' computers.

With the recorded information, the students changed grades and accessed English, science and history exams, some at the honors and Advanced Placement levels, authorities said.

While the students and Lai could face criminal charges, none have been filed. The search warrant indicated police were investigating possible felony counts.

Corona del Mar sophomore Skyler Gullick addressed the board meeting, saying the trustees made the right decision.

"It's a really serious crime," she said. "I don't think they knew how serious it was."

Before the vote, many parents and students addressed the board. Emotion ran high. Some parents feared colleges might view all students coming from the school as cheaters.

"I'm concerned about my daughter's college applications and how those schools are going to be looking at those," said Michele Caston, the mother of a senior not implicated in the scandal.

Randy Zuckerman, who said he is a friend of several of the parents whose children were expelled, spoke to the crowd on behalf of the families of three of the 11 students. He said they did not participate in the cheating but knew about it and did not report it.

"Knowing cheating is taking place is not reason enough to be expelled," he said later. "These kids are humiliated. They can't unring this bell."

Others said that the board's decision needed to be a strong deterrent to future cheaters.

"This isn't run-of-the-mill cheating," said Yolanda Newton, a Newport Harbor High parent. "This was premeditated, sophisticated and ongoing."

She asked the board to expel the students and refuse to let them attend neighboring schools.