Persuading Judges to Admit Collateral Evidence Outside the Immediate Facts of the Case

This guide summarizes how outside evidence – here, called “Collateral Evidence” – can be used to support defenses to criminal charges and give juries a more complete understanding of your case’s dynamics and people’s motives to testify.

What is Collateral Evidence?

A collateral issue is an issue regarding a matter which is tenuously connected to the merits of the case. A trial court can admit or exclude evidence of collateral matters, depending upon the peculiarities of the case. Under evidence rules, court rules and case law; evidence on collateral issues can be relevant, if the fact that it tends to establish will tend to prove or disprove a fact at issue. For example – and hypothetically speaking – let’s assume a defendant is charged with assault. The defense is self-defense. One important issue will be whether the defendant or the victim was the first aggressor. Another issue is WHY the defendant responded in self-defense. Did the defendant know the victim was violent and/or mentally ill? Was the defendant assaulted by the victim in the past? In these situations, certain evidence rules allow the defendant to show the victim’s quarrelsome or violent disposition to be known to the jury. On the related issue of whether the defendant had a reasonable apprehension of danger, evidence demonstrating the victim’s use of deadly weapons and quarrelsome disposition is possibly admissible. In these cases, collateral evidence could take the form of the victim’s prior bad acts, mental health examinations, criminal history, acts of aggression indicating a violent disposition, school disciplinary records, etc. All of these facts are potential collateral evidence which might be admissible to a jury.

How Do Judge’s Decide Whether Collateral Evidence Is Acceptable?

Under evidence rules, case law and court rule; Judges may properly exclude evidence which would have a tendency to mislead, distract, confuse, waste time, or be too remote. However, to be relevant, collateral evidence need not establish the proponent’s case theory in and of itself, but it must be at least a piece of the puzzle underlying the facts of the case itself. Collateral evidence must be material and relevant to the matters which are sought to be proved. Through motions in limine and other pleadings, a competent criminal defense attorney will inform the Prosecutor and Judge of their intentions to elicit collateral evidence through the Prosecutor’s “victim” as possible rebuttal evidence should the victim hold themselves out as flawless and pure as the driven snow. The Court shall exercise reasonable control over the mode and order of interrogating these witnesses/victims and presenting evidence so as to (1) make the cross examination effective for the ascertainment of the truth, (2) avoid needless consumption of time, and (3) protect the victim/witness from harassment or undue embarrassment.

What Are Some Examples of Collateral Evidence?

CPS Records, School Records, criminal history (with some exceptions), lawsuits between the parties, the defendant’s past negative contacts with State’s witnesses and/or the victim, etc. Competent defense attorneys are creative in this regard. Basically, any facts which may help clarify the dynamics of a case and/or relevantly challenge the credibility of witnesses and victims are fair game as collateral evidence to be used at trial.

How Do I Obtain Good Collateral Evidence & Get It Admitted?

Experienced attorneys try arguing motions to allow specific and specialized information from particular witnesses who have the authority, background and/or experience who are qualified to speak about the proposed collateral evidence. Some may try persuading judges to sign a Subpoena Duces Tecum (discussed in another legal guide). Other experienced attorneys try admitting collateral evidence by arguing pretrial motions to the judge. Understandably, opposing counsel will undoubtedly object that your proposed collateral evidence is inadmissible hearsay, irrelevant, confusing and/or a waste of time. Consequently, a competent defense attorney will seek collateral evidence that tends to “stand by itself” and survive the inevitable flurry of objections from opposing counsel. These matters require extensive legal research, knowledge of the law, substantive defenses and criminal procedure. At any rate, hire an experienced criminal defense attorney who is knowledgeable in the rules of evidence, court rules and case law on getting collateral evidence admitted. Good luck!