If of a type reasonably relied upon by experts in the particular field in forming opinions or inferences upon the subject, the facts or data need not be admissible in evidence.
Federal Rule of Evidence 703 establishes the basis on which experts may form their opinions. Such opinions are needed for a jury to understand the facts in a case and the evidence before them.
For the purpose of attacking the credibility of a witness, evidence that he has been convicted of a crime is admissible but only if the crime (1) was punishable by death or imprisonment in excess of one year under the law under which he was convicted or (2) involved dishonesty or false statement regardless of the ...
(1) while testifying, or (2) before testifying, an adverse party is entitled to have the writing produced at the hearing, to inspect it, to cross-examine the witness thereon, and to introduce in evidence for the purpose of impeachment those portions which relate to the testimony of the witness.
If scientific, technical, or other specialized knowledge will assist the trier of fact to understand the evidence or to determine a fact in issue, a witness qualified as an expert by knowledge, skill, experience, training, or education, may testify thereto in the form of an opinion or otherwise.
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.
Evid. 703. The facts or data in the particular case upon which an expert bases an opinion or inference may be those perceived by or made known to the expert at or before the hearing.
Compromise Offers and Negotiations. (2) conduct or a statement made during compromise negotiations about the claim — except when offered in a criminal case and when the negotiations related to a claim by a public office in the exercise of its regulatory, investigative, or enforcement authority.
Evid. 403. Although relevant, evidence may be excluded if its probative value is substantially outweighed by the danger of unfair prejudice, confusion of the issues, or misleading the jury, or by considerations of undue delay, waste of time, or needless presentation of cumulative evidence.
Rule 611. of interrogating witnesses and presenting evidence so as to (1) make the interrogation and presentation effective for the ascertainment of the truth, (2) avoid needless consumption of time, and (3) protect witnesses from harassment or undue embarrassment.