Mueller says he would not go beyond anything in his report if he appears before Congress

Special counsel Robert S. Mueller III announced Wednesday he was closing his office and offered his first public comments on the results of his work, asserting that Justice Department legal guidance prevented him from accusing the president of a crime and noting cryptically that the Constitution “requires a process other than the criminal justice system to formally accuse the president of wrongdoing.”

Standing alone on stage in a room on the Justice Department’s seventh floor normally used for press conferences, Mueller said he was “speaking out today because our investigation...