https://www.vanityfair.com/news/2019/05/robert-mueller-statement?fbclid=IwAR0YoKdx7DkGO6jj8RrrkqKhuyzQcHEL-tVxmODq4ZmxlftPkWw5E7OeM14
"Addressing reporters, Mueller effectively objected to the Attorney General’s description of his findings, specifically Barr’s characterization of the report as exonerating Trump on obstruction. “If we had confidence after a thorough investigation of the facts that the president clearly did not commit obstruction of justice, we would so state,” Mueller said Wednesday. “Based on the facts and the applicable legal standards, however, we are unable to reach that judgment.” In other words, it’s very possible Trump committed a crime. Mueller went on to note that it was the Justice Department’s legal guidance, which prohibits the indictment of a sitting president, that prevented him from accusing Trump as such. He went on to shame the president, though not by name, noting that “When a subject of an investigation obstructs that investigation or lies to investigators, it strikes at the core of their government’s effort to find the the truth and hold wrongdoers accountable.” Perhaps most important, Mueller suggested that if Trump is to be held to account, it must be Congress that takes up the case. “The Constitution requires a process other than the criminal justice system to formally accuse a sitting president of wrongdoing,” he said. In other words: Congress, do your job and impeach."