Ben Carson was feisty. He was mocking. He was unyielding. And he was unexpectedly theatrical.

Mr. Carson, the doctor whose soft-spoken and sedate style has made his rise to the top of the Republican presidential field all the more puzzling, abandoned his gentle manner on Friday night and delivered a powerful public scolding of the news media that has begun to question his celebrated biography.

In the process, he turned what has become an almost robotic ritual for candidates under attack — the live and often defensive news conference — into an aggressive confrontation, and at times interrogation, of the reporters’ motives and methods.

“Don’t lie,” he told them, interrupting a journalist’s question.

“That is a silly argument,” he said to another.

In a stern admonition to the journalists standing just feet away, Mr. Carson declared, “The American people are waking up to your games.”