Guilt in U.S. law

This is an essay about the meaning of the word "guilt" under the laws of the United States of America.

In ordinary English usage, the opposite of "guilt" is "innocence," and either word usually carries a connotation of moral evaluation. In the field of law, however, that concept of "guilt" is of negligible importance because "guilt" or "innocence" is a question of fact whose truth it is often impossible to discover, much less to prove to a legal standard, which is why the system concerns itself with "justice" instead of "truth." (In the same way that engineering may be viewed as the practical application of "pure" science to the real world, law may be viewed as the application of moral precepts.) Paradoxically perhaps, the entire field of criminal law revolves around the idea of "guilty," whose opposite is "not guilty." In the language of statistics, the "null hypothesis" in a criminal case is always "The defendant is not guilty," never "The defendant is innocent" or "The defendant is guilty," so if the prosecution disproves the null hypothesis with evidence at or above the applicable "confidence level" (called in law the "standard of proof"), the conclusion (called in law the "verdict") is "The defendant is guilty." In this essay, the factual matter will be referred to as "actual guilt" or "actual innocence," and the legal matter as "legally guilty" or "legally not guilty," and if the modifier "legal(ly)" is not specified, it is to be understood. Thus, the possible verdicts of "guilty" and "not guilty" are to be read as meaning "legally guilty" and "not (legally) proved guilty," respectively.