4-Step Process of Admissibility

4-Step Process of Admissibility

Judge Birmingham has accepted an invitation to give a lecture entitled “Evidentiary Mechanics” at the 26th Annual Texas Bar College CLE for the General Practitioner in Galveston, Texas. He will share his 4-step process of admissibility, a unified way for the practitioner to solve any evidentiary problem.

The lecture is a summary of Judge Birmingham’s freely available evidence casebook called “Evidentiary Mechanics: Delivering Information to the Factfinder.”

I. 4 Step Process of Admissibility

A trial is a well-regulated fact-finding mission in which jurors are called upon to answer a question: do they believe beyond a reasonable doubt that the person on trial is guilty of the crime charged? Their answer depends upon the evidence provided to them during the trial by both sides. Evidence is any fact, circumstance or object that is any part of a crime; it is a trace of human agency, the remnant of some criminal activity. Since the rules of evidence filter the information the factfinder can consider, it is not accurate to say that a verdict in a particular case was based on all facts, circumstances, and witnesses to a particular crime. It is more accurate to say that the verdict was based on all facts and circumstances the rules of evidence allowed the factfinder to hear.
Evidence comes in many different forms: a witness’s description of an observed act or event, a photograph, a video, a fingerprint, forensic testing results, or some opinion from an expert witness. However, no matter what form the evidence takes, the admissibility of all evidence can be determined by following this 4-step process of admissibility: the practitioner must establish that a witness with (1) a proper basis of knowledge (2) can accurately depict a fact, circumstance, or object (3) that was lawfully obtained and (4) relevant. We will briefly discuss each step in order.

First, the practitioner must establish that the witness has the proper basis of knowledge regarding the information they are called upon to testify. The rules tell us that there are two proper bases of knowledge: personal experience or expert testimony. Before any witness can be called upon to recount anything they have seen or heard, the practitioner must establish that they did so personally. For example, that they personally saw the man in the mask run away from a crime scene, or heard cries of distress from a robbery, or overheard their friend confess to murder. We commonly refer to this type of witness as a lay-witness or lay-testimony. The second type of “proper knowledge” under this heading is expert testimony. Before a witness can be allowed to give their expert opinion, they must be qualified as an expert. The practitioner for this type of witness must first establish that the witness has the proper training and experience to give some type of expert opinion. Only when the practitioner establishes that the witness either has personal experience or expertise about the subject matter of their testimony, can the practitioner move on to the second part of our admissibility process.

Second, the information must be sufficiently trustworthy and accurate according to a constellation of evidentiary rules and predicates related to personal opinions, expert opinions, authentication, and hearsay. Consider a few examples. When a person has observed something for themselves, Rule 602 establishes that their observations are accurate enough to be considered by a jury; if a person is qualified as an expert, then Rule 702 establishes how the opinion may be considered accurate enough to be considered by a jury; when a person claims that someone confessed a murder to them, Rule 803(24) establishes how this out of court statement may be considered accurate enough to be heard by a jury. Only when the practitioner has (1) established that the witness has the proper basis of knowledge and (2) has offered it according to a rule establishing that the matter is trustworthy and accurate can the practitioner move on to the third step.

In this third step, we must account for the intersection of the rules of evidence and the constitutional protections to establish that the evidence was lawfully obtained. Even though the proper basis of knowledge has been established and the practitioner has established the testimony is accurate, if the evidence was unlawfully obtained or given in such a way as to violate the Constitution, it would not be admissible. Thus, even if an officer personally observed some contraband in a suspect’s house but didn’t have the authority to be there, whether by warrant or some exception to the warrant requirement, the evidence would not be admissible because it was obtained in violation of the 4th Amendment. Even though a police officer may have personally witnessed a victim of intimate partner family violence fill out a sworn affidavit recounting their attack that satisfied some hearsay rule, the affidavit may nonetheless be inadmissible because of a potential 6th Amendment confrontation clause violation. The same could apply for a confession obtained in violation of the Miranda warnings: even if the officer personally observed the interview, and the defendant made statements that satisfy the hearsay rules, the confession would be inadmissible. Only after the practitioner has established that the witness has the proper basis of knowledge in step one, can deliver the information accurately according to the rules in step two and that the evidence was lawfully obtained can they move into the final step: relevancy.

Fourth, we consider whether the evidence is relevant. Even if evidence was personally observed, accurate according to one of the rules, and lawfully obtained, the evidence could only be admissible if it is relevant, which is to say both probative and not unduly prejudicial. Relevance is case specific and fluid. What is relevant in one trial may not be relevant in another, or what is irrelevant at the beginning of a trial may be relevant by the end. But in all cases, for all types of evidence any witness may offer, the evidence must be relevant. If it is not relevant, it is not admissible.

This 4-step process should be followed in the order presented. A court could not really consider whether an out of court statement is hearsay without first hearing from the witness who actually heard the declarant speak the out of court statement. Nor could a court meaningfully consider whether a defendant’s confession was lawfully obtained without first hearing from a witness who personally heard it who could establish that the defendant is in fact the person who confessed. Finally, the value or relevance of a piece of evidence could not be considered without a court first determining who said it and whether a rule has established its trustworthiness. All 4 steps must be satisfied for a piece of evidence to be admitted. If the practitioner fails at any one step, there is no need to consider the question any further.


In addition to the casebook, I have created a freely accessible database you can access here: A Practitioner’s Guide. This dynamic caselaw database stores all of the cases discussed in Evidentiary Mechanics, divided into 4 categories: authentication, hearsay, impeachment, and Constitutional law. The interactive table lists the applicable rule from each case along with a link to the full text of the case itself. When I created the database, I envisioned that the practitioner could have it open on a tab on their laptop during trial for easy and quick access to approximately 75 of the most useful cases for the Texas Trial Lawyer.