I have subpoenaed witnesses, as is my right, and non-attendance or other non-compliance by one under subpoena has consequences under a Court's contempt powers.
The subject matter of the hearing is a matter of courthouse record, per the cause number. It is largely irrelevant to this post, which is more general than specific, but being both, and being about the rights of any individual feeling wrongly attacked in a court proceeding.
In calling witnesses to testify at a show cause hearing, the Court has discretion, depending on circumstances and judgment of the Judge hearing matters, to allow (when appropriate) extensive probative evidence of the kind permitted by these few mostly sequential rules of evidence (online, here) [note, bolding in the original, some italics added for emphasis]:
Rule 404. Character Evidence Not Admissible to Prove Conduct; Exceptions; Other Crimes
(a) Character evidence generally. Evidence of a person’s character or a trait of character is not admissible for the purpose of proving action in conformity therewith on a particular occasion, except:
(1) Character of accused. Evidence of a pertinent trait of character offered by an accused, or by the prosecution to rebut the same;
(2) Character of victim. Evidence of a pertinent trait of character of the victim of the crime offered by an accused, or by the prosecution to rebut the same, or evidence of a character trait of peacefulness of the victim offered by the prosecution in a homicide case to rebut evidence that the victim was the first aggressor.
(b) Other crimes, wrongs, or acts. Evidence of another crime, wrong, or act is not admissible to prove the character of a person in order to show action in conformity therewith. It may, however, be admissible for other purposes, such as proof of motive, opportunity, intent, preparation, plan, knowledge, identity, or absence of mistake or accident. [...]
Rule 405. Methods of Proving Character
(a) Reputation or opinion. In all cases in which evidence of character or a trait of character of a person is admissible, proof may be made by testimony as to reputation or by testimony in the form of an opinion. On cross-examination, inquiry is allowable into relevant specific instances of conduct.
(b) Specific instances of conduct. In cases in which character or trait of character of a person is an essential element of a charge, claim, or defense, proof may also be made of specific instances of that person’s conduct.
Rule 406. Habit; routine Practice
Evidence of the habit of a person or of the routine practice of an organization, whether corroborated or not and regardless of the presence of eyewitnesses, is relevant to prove that the conduct of the person or organization on a particular occasion was in conformity with the habit or routine practice.
Rule 407. Subsequent Remedial Measures
When, after an injury or harm allegedly caused by an event, measures are taken which, if taken previously, would have made the event less likely to occur, evidence of the subsequent measures is not admissible to prove negligence, culpable conduct, a defect in a product, a defect in a product’s design, or a need for a warning or instruction. This rule does not require the exclusion of evidence of subsequent measures when offered for another purpose, such as proving ownership, control, or feasibility of precautionary measures, if controverted, or impeachment.
Rule 806. Attacking and Supporting Credibility of Declarant
When a hearsay statement, or a statement defined in Rule 801(d)(2)(C), (D), or (E), has been admitted in evidence, the credibility of the declarant may be attacked, and if attacked may be supported, by any evidence which would be admissible for those purposes if declarant had testified as a witness. Evidence of a statement or conduct by the declarant at any time, inconsistent with the declarant’s hearsay statement, is not subject to any requirement that the declarant may have been afforded an opportunity to deny or explain. If the party against whom a hearsay statement has been admitted calls the declarant as a witness, the party is entitled to examine the declarant on the statement as if under cross-examination.
I put that last item in, so that if, for example, a court record from another instance of litigation involving a party is introduced, that party can attack the character, motive, bona fides, etc., of the declarant - the person authoring or offering the document in the other proceeding, but not a witness in person in the underlying dispute.
However, as with all matters before a Judge, credibility is weighed in part by demanor and conduct, so that delicacy in using rules is important.