lionheart's link in the last thread was good.
Four Principles for Reading the Mueller Report
www.lawfareblog.com/four-principles-reading-mueller-report
if Mueller declines prosecution [...], onlookers should presume that those decisions also reflect reasonable prosecutorial judgments.
Declinations in a politically sensitive matter of this type may happen for a variety of reasons. The facts may not be adequate to support a given prosecution. Particularly with respect to the president, there are major legal impediments to prosecution—both with respect to the application of specific statutes to the exercise of Article II powers and with respect to the threshold question of whether the president is amenable to indictment while he remains in office at all.
[...]
. the report only covers what it covers. There may be many lines of inquiry the public feels are relevant to L’Affaire Russe, or to ethical and legal questions about the president and his family more generally, that are not within the scope of the Mueller report.
[...]
if Mueller finds a series of facts and concludes that those facts either do not amount to a prosecutable case or that some law bars his bringing that case, people are free to judge those facts. Fact patterns that Mueller may choose not to prosecute, or may be barred from prosecuting, may nonetheless warrant the opprobrium of all decent people. They may warrant impeachment and removal from office—the standards for impeachment being quite different from the standards of the criminal law. They may warrant civil liability.