A law school student upset about his grades went on a shooting spree Wednesday, killing three people and critically wounding three others before he was wrestled to the ground by students, officials said.

The victims included the dean of the Appalachian School of Law and a professor who were gunned down in their offices. The third person slain was a student, said Ellen Qualls, a spokeswoman for Virginia Gov. Mark Warner.

Briggs said he had treated the suspect in the past year. He described the gunman as a Nigerian in his early 40s who had flunked out last year and been allowed to return.

“I think they were getting ready to tell him that he had not made the grade this year,” Briggs said.

Dean L. Anthony Sutin and the professor were “executed” in their offices, Briggs said.

He said the gunman then went downstairs into a common area and opened fire on a crowd of students, killing one and wounding three others. He was tackled by four male students as he left the building.

The three wounded students were taken to Buchanan General Hospital, Qualls said. The governor said they were in critical condition.

–Associated Press