(CNN) A student who opened fire Friday inside a suburban Denver high school appears to have been seeking revenge against a faculty member because of a “confrontation or disagreement,” the Arapahoe County sheriff said.

The shooter, identified as 18-year-old Karl Halverson Pierson, shot one student before turning the gun on himself and taking his own life, Sheriff Grayson Robinson told reporters.

The shooting began after the student walked into Arapahoe High School in Centennial with the intention of confronting a specific faculty member, Robinson said.

“The suspect has been found inside the school and he has deceased as a result of what appears to be a self-inflicted gunshot wound,” Robinson said in one of his first statements after the shooting.

Authorities revised downward the number of students wounded in the shooting to one. Two students were previously reported to have suffered gunshot wounds. But Robinson said Friday night that an investigation concluded there was only one after it was discovered that blood on another person was from the sole victim.

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