Expert Witness Cross
Examination
Heather A. Salg
Harris, Karstaedt, Jamison & Powers,
P.C.
hsalg@hkjp.com
WHY IT MATTERS
• If you haven’t precluded the expert, they must be
testifying on about some contested issue that
requires special knowledge, training or
experience:
– Economic valuation
– Etiology of physical complaints
– Causation of a particular event
• Undermining the other side’s expert is far more
persuasive than putting on a defense expert
UNDERSTAND THE SCIENCE
• What is this expert’s opinion?
• What is the basis for this expert’s opinion?
• Where is the expert the strongest?
– Generally it will either be good science or good
presentation
• Where is the expert the weakest?
– Conversely it will generally be bad science or bad
presentation
• Unless you understand the science, you will not
be able to figure out the strengths and
weaknesses of the expert
METHODS TO GAIN UNDERSTANDING
• Start by carefully reading the expert’s report
– Highlight what you do not understand.
• Research
– Start with Google, save your client time & money
• Use your expert’s expertise
– Ask your expert where the opposing expert is
weakest
• Peer reviewed studies
– Establish “learned treatises” in depositions
GENERAL RULES FOR EXPERT CROSS
• Never ever ask a question you don’t know
the answer to…. unless the answer does not
matter.
• Cross examination of experts is one of the
most exciting parts of trial. It can win or lose
your case… if you make it exciting right from
the start. Don’t wait to get to the good stuff.
Structure of Cross Examination
• If the expert’s weakness is presentation,
spend a fair amount of time on qualifications.
Assuming the expert survived a 702 challenge,
consider whether to challenge expert during
voir dire… be mindful of Judge
• Make sure you have an up to date testimony
list … up to date within a month of trial
• Be thoughtful about whether to cross on
expert charges
Establishing Context and Use of
Headnotes
• Quickly and Concisely direct the expert to the
opinion at issue:
– Doctor, you’ve opined that MTBI symptoms can
worsen over time, even when the injuries are of the
type present in this case.
• Direct the expert to the basis for that opinion:
– For that, you cited Biegler…
• Show that the reliance on that source was
inappropriate.
– True that the Biegler article excluded injuries of the
type present in this case?
Do Not Get Pushed Around
• “Well, counselor, if you had read that article
you would know that, xxx”
• READ ALL SOURCES YOU INTEND TO CITE
• “Doctor, I’m sure there are a lot of things you
want to tell us, and Mr. Plaintiff’s Attorney will
have the opportunity to elicit your testimony
in that regard. But for now, I would like you to
answer my question, which was x.”
Evidence
• Nothing will weaken cross examination faster
than disorganization
• Have every question in front of you, every
citation at your fingertips, every exhibit ready
to show the jury.
• Never allow the expert to “look in the file” for
something…. Unless the information the
expert relied on doesn’t exist.
Manage the Expert
• Within 10 minutes of cross, the expert should
understand how prepared you are.
• You are looking for the, “If you say that is what
the record says, I trust that it what it says”
response. It will move cross examination along
more quickly which will hold the jurors interest.
• Do not draw an admonishment. Do not cut off or
interrupt the expert. Jury should feel that nothing
this expert can say worries you. (Also
admonishment can hurt your credibility and
improve the witness’ credibility).
Very Last Resort
• “Your honor, I respectfully request that the
court instruct the witness to answer the
question asked.”
• Try to avoid this unless absolutely necessary.
Impeach
• Cross examination outline – yes or no questions with
only the occasional call for a narrative to break up the
monotony, and those must be carefully controlled.
• Every question/statement should be followed by a cite.
• Impeach: Confirm, Credit, Confront.
– Doctor, today you testified x.
– You remember that I had the opportunity to ask you some
questions under oath previously, in your deposition?
– I am showing you your transcript, p. 56, line 5, please read
along with me…
Terminology/Lingo
• Scientific terminology/lingo is virtually
unavoidable with experts.
• Make sure to define those terms clearly and
concisely for the jury.
• Look at the jury, are they understanding what
you are talking about?
• Helping them understand will make you look
more credible and will mitigate “expert”
mythos
Presentation
• Think about how you are going to present
• Do not be unduly aggressive
• Letting your skepticism show may be
appropriate where expert is less credible
– Be aware of your presentation
• The jury can tell when you are annoyed. It had
better be for a good reason.
End Strong
• Even if you are going to stop after a court
admonishes the witness.
• Make sure that the jury is left with your strong
point