In-Depth Notes on Rules of Evidence and Expert Witnesses

GENERAL OVERVIEW OF EVIDENCE RULES

  • Legal evidence rules govern how evidence is presented in court.
  • The judicial process is adversarial where the judge acts as the referee.
  • Evidence rules derive from case law and statutes, primarily the Indiana Rules and Federal Rules of Evidence.
  • Aim is to ensure reliability and trustworthiness of the evidence presented to a jury.
  • Judges must balance probative value against potential harm or impropriety of evidence.

RELEVANCE IN EVIDENCE

  • Definition of Relevance: Evidence must prove or disprove a material fact.

    • It should help determine the likelihood of a material fact.
    • A material fact is consequential to the case, affecting the outcome.

  • Consideration of Prejudicial Evidence:

    • Relevant evidence may still be excluded if it is overly prejudicial.
    • Evidence must not lead a jury to convict based on emotional reactions rather than facts.
    • Must assess if the probative value outweighs its prejudicial effect.

  • Examples of Prejudicial Evidence:

    • Gruesome crime scene photos.
    • Statements by defendants suggesting biases (e.g., having connections with law enforcement).
    • Possession of unrelated explicit materials.

HEARSAY RULE

  • Definition (Rule 801):

    • Hearsay involves statements made outside of court not presented during testimony.
    • It is aimed to prove the truth of the asserted matter.
    • Key elements of hearsay include:
      • Statement: Oral, written assertion, or nonverbal conduct intended as an assertion.
      • Declarant: The individual making the statement.
      • Hearsay is either true or false but not established within the courtroom.

  • Identifying Hearsay:

    • Example: "John told me he saw Rick shoot her" is hearsay.
    • Example: "I saw Merle with a gun" - does not qualify as hearsay if the witness observed this directly.

  • Hearsay Exceptions:

    • Dying declarations.
    • Statements against interest.
    • Evidence must demonstrate reliability.

CHARACTER EVIDENCE

  • Character Evidence: Generally inadmissible to prove conduct.

    • This includes prior bad acts unless specified exceptions apply, often relevant during sentencing.

  • Special Considerations:

    • Competency of witnesses can affect evidence.
    • Children or mentally incompetent individuals may not understand the oath.
    • Limited admissibility of lay opinions based on personal experiences (e.g., intoxication).

TYPES OF EVIDENCE

  • Direct Evidence:

    • First-hand evidence that establishes a fact without needing inference.
    • Includes eyewitness accounts (e.g., seeing a crime occur) and some physical evidence (e.g., DNA).
    • Direct evidence may not always be conclusive due to witness reliability.

  • Circumstantial Evidence:

    • Requires inference to conclude a fact (e.g., fingerprints on a weapon imply guilt).
    • Does not necessarily involve direct observation.
    • Can be sufficient for conviction but is often less preferred by juries.

EXPERT WITNESSES

  • Expert witnesses can provide opinions to assist juries in understanding evidence or facts in question:
    1. Must hold special knowledge relevant to the case.
    2. Opinions must be based on sufficient and reliable facts/data.
    3. Their methods must be accepted and applied reliably within their area of expertise.

EXCULPATORY EVIDENCE

  • Any evidence that can question the guilt of the accused or mitigate punishment.
    • Brady v. Maryland establishes the state's disclosure duty regarding evidence favorable to the accused.
    • Evidence that is inadmissible or immaterial does not need to be disclosed.

IMPEACHMENT EVIDENCE

  • Evidence that undermines a witness's credibility, including prior statements and criminal history.
    • Indiana’s laws require disclosure of all such evidence to ensure fairness in the trial process.

SCIENTIFIC EVIDENCE ASSESSMENT

  • Differentiating between real and junk science:

    • Frye Standard: Evidence must be generally accepted in the scientific community (lie detector tests, for instance, were considered junk science under Frye).
    • Daubert Standard: Judges act as gatekeepers, ensuring evidence's scientific basis meets rigorous criteria (e.g., empirical testing, peer review).
    • Emphasis on avoiding bias, low error rates, and recognized methodologies are crucial for scientific evidence to be deemed admissible.

  • Types of Forensic Evidence include:

    • Fingerprints, DNA analysis, serology, and ballistics. Reliability of such evidence is pivotal to admissibility.