With the release of his first indictments and a surprise plea deal on Monday morning, Special Counsel Robert Mueller sketched a partial outline of his team’s investigation into Russian electoral meddling and took control of a news narrative that had been increasingly dominated by his conservative critics.

Legal experts said the court filings indicate Mueller is running a serious, deliberative, and far-sighted inquiry. “I would say this is High-Level Special Counsel Investigation 101,” said Richard Ben-Veniste, a member of the Watergate special-prosecutor task force. “Mueller is operating by the book …”

“[Mueller]’s setting up the scene,” said Ali Soufan, a former FBI agent who now runs a security firm called The Soufan Group. He noted that the special counsel could file additional charges in the future. “This indictment is a living document,” Soufan explained. “It’s going to continue to change based on the evidence and on the investigative strategy of the special counsel …”