B. Impeachment by Omission
In addition to his prior statements, a witness may also be impeached by pointing out that his current
testimony includes facts that were not included in his prior statements or testimony. This type of
impeachment follows the same theory as impeachment by a prior inconsistent statement; the witness’s
current testimony is rendered less credible because when she told the same story earlier it did not
contain facts that she now claims are true. In essence, the impeachment is saying, “do not believe this
witness because she is adding facts to her story.” Or, in other words, “If these things are true, why didn’t
she say them before?”
In mock trials it is easy to see what is really taking place when facts are included at trial that are not
found in the case file: they are either reasonable inferences from the case materials that explain the
events of the case or they are unreasonable inferences that bolster the witness’s testimony. As
discussed in previous chapters, witnesses in mock trials are allowed to make reasonable inferences from
the case materials. Witnesses are not, however, allowed to go beyond reasonable inferences by making
up material facts in order to strengthen their side of the case. So, if they are not supposed to make up
facts, why do so many teams do it? Unfortunately, teams make up facts because they forget that mock
trial competitions are not about getting a verdict in their favor; they are about demonstrating trial
advocacy skills. Making up facts is unethical. Accordingly, it is not unheard of for judges to penalize
teams who make unreasonable inferences from the case file. Some judges even believe it should be
cause for automatic loss of the competition round.
Nevertheless, you may encounter teams who make up material facts during your trials. When that
happens, you cannot simply object and say, “Your Honor, she is making up that fact – it isn’t in the case
file!” Mock trial attorneys must stay in character and deal with surprises the same way trial lawyers do:
by impeaching the witness by omission. This, learning the steps of an effective impeachment by
omission is just as important for mock trial participants as is learning to impeach by prior inconsistent
statement.
When impeaching by omission, follow these three general steps: (1) recommit; (2) accredit; and (3)
confront. Recommit the witness to the new testimony she gave during the trial. Next, accredit the
witness’s previous testimony, emphasizing that she swore to tell the whole truth and also that she had
an opportunity to read her statement to make sure she included all relevant facts. Finally, confront the
witness with the fact that she did not include these new assertions in her previous testimony.
1. Recommit the witness
Recommit the witness to having testified to a certain fact during direct or cross examination.
QUESTION: Professor Geraghty, you told us during your direct examination that you spoke to
the dean on January 6, right?
Or,
QUESTION: Professor Geraghty, today you told the jury that you had a conversation with the
dean on January 6, right?
2. Accredit the witness’s prior opportunity to tell the full story
If your case file includes witness statements or affidavits, it is reasonable to conclude that each of
the witnesses was given the opportunity to tell their story in full therein. After all, both witness
statements and affidavits are summaries of the witness’s testimony and summaries include all the
important facts. Likewise, if your witness was given the opportunity to read over her deposition and add
any information relevant to the case. Thus, if the prior testimony was in the form of an affidavit, the
accreditation might proceed as follows:
QUESTION: You recall giving a statement in this case, right?
QUESTION: When you gave that statement you were under oath?
QUESTION: You swore to tell the truth, the whole truth, and nothing but the truth?
QUESTION: That was the same oath that you took here in court today?
QUESTION: When you were asked to give that statement, you were told to include all relevant
information, right?
QUESTION: Then, when you were done writing it, you were asked to read it over?
QUESTION: To make sure it was accurate and complete?
QUESTION: And you did that, didn’t you?
QUESTION: You were able to make any corrections or additions that you wanted?
QUESTION: When you were done, you signed the statement affirming that it was accurate and
complete, right?
3. Confront the witness
Here is where you point out that the witness testified to facts that were not included in his affidavit
or deposition:
QUESTION: Professor Geraghty, isn’t it true that nowhere in your affidavit did you mention
talking to the dean on January 6?
You can also give the witness a copy of his affidavit or deposition transcript and ask him to indicate
where he included the pertinent fact. The advantage of this method is that it allows the fact-finder to
hear the witness’s admission, in his own words, that the fact was not included. The downfall of using
this method in mock trial competition is that it takes more time to execute than the method outlined
above. Given the time limits typically set in mock trials, it is not wise to waste even one minute on
having an opposing witness authenticate his own affidavit and then read through it to look for a
pertinent fact. To be sure, there is always a risk that the witness will take the time to read his entire
affidavit before answering – in which case one minute can easily become five. But, if you can spare the
time, the confrontation might go as follows:
QUESTION: Professor Geraghty, this is your affidavit, isn’t it?
QUESTION: Directing your attention to the last page. That is your signature, is it
not?
QUESTION: Please read through your affidavit, Professor Geraghty, and signal
me when you have finished.
QUESTION: Isn’t it true that nowhere in your statement did you say that you spoke
to the dean on January 6?
Impeachment
General purpose:
To hurt the credibility of an opposing witness or to bring in evidence that the witness will not
admit.
When to use:
When a witness contradicts their affidavit. They can either directly contradict something they
said in the affidavit, or make up something that reasonably should have been in the affidavit. If
impeaching over something said on direct examination, it should be done at the very beginning
of the cross examination.
When not to use:
Do not impeach for trivial information. Any information that does not give the opposing team an
advantage is not worth impeaching over.
Structure:
1. Make witness restate inaccurate testimony
“Is it your testimony today that ____?”
2. Lay foundation for affidavit
a. “You gave a statement prior to trial today, correct?
b. “And while giving this statement, you were under oath?”
c. “After giving this statement, you checked it for completeness and accuracy, didn’t
you?”
3. Approach the witness
a. “Your honor, may I approach the witness?”
b. If impeaching by contradiction, “Let the record reflect that I will be referring to the
witness’s affidavit, paragraph ____.”
c. If impeaching by omission, “Let the record reflect that I will be referring to the
witness’s affidavit in its entirety.
4. Question witness
a. “This is your affidavit, isn’t it?”
b. “This is your signature on the last page?”
c. If impeaching by contradiction, “Please read silently as I read aloud, (read inconsistent
information). It says that, doesn’t it?”
d. If impeaching by omission, “It says nowhere in this affidavit that (invented fact), does
it?”