Alan the Noble:
Virtually everybody agrees that, in the normal case, a prosecutor should never go beyond publicly disclosing that there is insufficient evidence to indict. No responsible prosecutor should ever suggest that the subject of his investigation might indeed be guilty even if there was insufficient evidence or other reasons not to indict. Supporters of Mueller will argue that this is not an ordinary case, that he is not an ordinary prosecutor and that President Trump is not an ordinary subject of an investigation. They are wrong. The rules should not be any different.
Remember that federal investigations by prosecutors, including special counsels, are by their very nature one-sided. They hear only evidence of guilt and not exculpatory evidence. Their witnesses are not subject to the adversarial process. There is no cross examination. The evidence is taken in secret behind the closed doors of a grand jury. For that very reason, prosecutors can only conclude whether there is sufficient evidence to commence a prosecution. They are not in a position to decide whether the subject of the investigation is guilty or is innocent of any crimes.
That determination of guilt or innocence requires a full adversarial trial with a zealous defense attorney, vigorous cross examination, exclusionary rules of evidence and other due process safeguards. Such safeguards were not present in this investigation, and so the suggestion by Mueller that Trump might well be guilty deserves no credence. His statement, so inconsistent with his long history, will be used to partisan advantage by Democrats, especially all those radicals who are seeking impeachment.