Conn. Crim. Jury Instr. 2.5-1

In this case certain witnesses have taken the stand, given their qualifications and testified as

expert witnesses. A person is qualified to testify as an expert if he or she has special

knowledge, skill, experience, training or education sufficient to qualify him or her as an expert

on the subject to which the testimony relates. An expert is permitted not only to testify to facts

that he or she personally observed but also to state an opinion about certain circumstances. This

is allowed because an expert, from experience, research and study, generally has a particular

knowledge of the subject of the inquiry and is more capable than a lay person of drawing

conclusions from facts and basing an opinion upon them.

[<If hypotheticals were used:>

1 An expert witness may state an opinion in response to a

hypothetical question, and some experts have done so in this case. A hypothetical question is

one in which the witness is asked to assume that certain facts are true and to give an opinion

based on those assumptions. The value of the opinion given by an expert in response to a

hypothetical question depends upon the relevance, validity and completeness of the facts he or

she was asked to assume. The weight that you give to the opinion of an expert will depend on

whether you find that the facts assumed were proved and whether the facts relied on in reaching

the opinion were complete or whether material facts were omitted or not considered. Like all

other evidence, an expert’s answer to a hypothetical question may be accepted or rejected, in

whole or in part, according to your best judgment.]

In this case you were provided expert testimony by the following witnesses: <list the expert

witnesses>.

Allowing someone to give expert testimony is in no way an endorsement by the court of the

testimony or the credentials of the witness.

Such testimony is presented to you to assist you in your deliberations. No such testimony is

binding upon you, and you may disregard the testimony either in whole or in part. It is for you to

consider the testimony with the other circumstances in the case, and, using your best judgment,

determine whether you will give any weight to it, and, if so, what weight you will give to it. The

testimony is entitled to such weight as you find the expert’s qualifications in his or her field

entitle it to receive, and it must be considered by you, but it is not controlling upon your

judgment. You are also to consider his or her general credibility in accordance with the

instruction on credibility applicable to all witnesses.

1 See State v. Michael G., 107 Conn. App. 562, 570 (finding error in court’s failure to give

requested charge on the factual basis of an expert’s opinion based on a hypothetical question),

cert. denied, 287 Conn. 924 (2008).