Deck 9: Opinions and Expert Testimony

Question 1

What is the general evidence rule relating to the admissibility of opinions of lay witnesses in a criminal case? Explain the rationale for this rule.

Answer 1

The general evidence rule relating to the admissibility of opinions of lay witnesses in a criminal case is that lay witnesses are typically not allowed to give opinions or draw conclusions in their testimony. Instead, they are expected to testify about facts that they observed or experienced firsthand.

The rationale for this rule is based on the idea that lay witnesses are not considered experts and therefore their opinions may not be based on sufficient knowledge or experience to be reliable. Allowing lay witnesses to give opinions could potentially confuse the jury and lead to the introduction of speculative or prejudicial information.

In criminal cases, the focus is on presenting factual evidence that can be objectively evaluated by the jury. Allowing lay witnesses to give opinions could undermine the fairness and reliability of the trial process. Therefore, the general rule is to limit lay witnesses to testifying about what they personally observed or experienced, rather than offering their opinions or conclusions.

Question 2

Explain the reasons for the exceptions to the opinion rule.

Answer 2

The opinion rule, which generally prohibits witnesses from testifying about their opinions or beliefs, has several exceptions. These exceptions are based on the idea that in certain circumstances, opinion testimony can be helpful to the trier of fact in understanding the evidence presented.

One reason for the exceptions to the opinion rule is expertise. If a witness has specialized knowledge or experience in a particular field, they may be allowed to offer their opinion on matters within that field. For example, a doctor may be permitted to give their opinion on a patient's medical condition based on their expertise and examination of the patient.

Another reason for the exceptions is lay witness opinion. Lay witnesses, who are not considered experts, may still be allowed to give their opinions on matters that are based on their personal observations or perceptions. For example, a witness may be allowed to testify that a person appeared angry or intoxicated based on their observations of the person's behavior.

Additionally, opinion testimony may be allowed if it is helpful to the trier of fact in understanding the evidence. In some cases, a witness's opinion may provide context or insight that is not readily apparent from the facts alone.

Overall, the exceptions to the opinion rule are based on the idea that in certain circumstances, opinion testimony can be valuable and informative to the trier of fact in reaching a just decision.

Question 3

Define opinion evidence, expert witness, and nonexpert witness.

Answer 3

Opinion evidence refers to testimony or evidence presented in court that is based on the witness's personal opinion or belief rather than on direct observation or knowledge of the facts. This type of evidence is often used to help the jury or judge understand complex or technical issues that require specialized knowledge or expertise.

An expert witness is a person who has specialized knowledge, training, or experience in a particular field and is called to testify in court to help the trier of fact (jury or judge) understand complex or technical issues. Expert witnesses are allowed to give opinion evidence based on their expertise and are often used in cases involving medical, scientific, or technical matters.

A nonexpert witness, on the other hand, is a person who testifies in court based on their personal knowledge or observations of the facts at issue in the case. Nonexpert witnesses are not allowed to give opinion evidence unless it is based on their personal perception or experience. They are typically used to provide factual information about what they saw, heard, or experienced.

Question 4

A nonexpert, or lay witness, may state a relevant opinion if three requirements are met. What are the three requirements? What is the effect of Federal Rule 701? May a witness give an explanation regarding the defendant's guilt?

Question 5

Explain how a lay witness may offer opinions on the same subject as an expert witness.

Question 6

A nonexpert witness is asked, "What was the appearance of the man at the time, with reference to his being rational or irrational?" Will an answer be allowed over the objection of the other party? Explain.

Question 7

When or under what circumstances may a lay witness give an opinion concerning another person's handwriting?

Question 8

What kind of foundation would have to be developed for a lay witness to offer an opinion that a person was intoxicated?

Question 9

A police officer testified, "In my opinion, the defendant was drunk." Under what conditions is this nonexpert opinion testimony admissible? Do the same rules apply in drug cases? May a nonexpert give an opinion regarding mental condition? What are the requirements?

Question 10

Rule 702 of the Federal Rules of Evidence defines the conditions under which expert testimony is admissible. What is the general rule relating to the use of expert testimony?

Question 11

In general terms, how does one qualify to testify as an expert witness? What kind of questions might be asked of a proposed expert in DNA evidence comparisons that would help qualify the person as an expert witness?

Question 12

Can a witness qualify as an expert when he or she does not have a degree or license? May the special knowledge necessary to qualify as an expert be derived from experience? May the fact that the expert does not have a degree or license be brought out at the trial?

Question 13

How has DNA evidence offered by expert become so important in many criminal cases?

Question 14

How does the defense attorney or prosecutor go about selecting an expert witness and having him or her qualified by the court?

Question 15

There are two avenues through which expert evidence may be presented to a jury. Briefly state these, and explain the differences between them.

Question 16

When an expert witness takes the stand, can his or her opinions be challenged in the cross-examination process? If so, what is the process for challenging these opinions?

Question 17

Common subjects of expert testimony are the physical and mental condition of a person. Is it necessary that the expert in such situations be a person licensed to practice medicine? If not, what are the qualifications?

Question 18

When an expert gives an opinion regarding handwriting, must he or she state that he or she is positive that the samples are identical? Does requiring a suspect to give a handwriting specimen violate the Fifth Amendment?

Question 19

Why do most courts exclude expert testimony explaining the results of polygraph examinations? Can polygraph examiners be qualified as expert witnesses? When can polygraph examination results be admitted into evidence through the use of expert testimony?

Question 20

How does a witness qualify as an expert in how drug traffickers operate? May a police officer testify as an expert witness when the case involves drug violations?

Question 21

Under what conditions may those who conduct a test in a crime laboratory testify concerning the significance of the test?

Question 22

In State v. Gonzalez, a police officer made a traffic stop of a woman who had been speeding, and after that smelled the odor of marijuana coming from inside the car. The officer noted some of the effects of marijuana appeared to be observable in the defendant, and at trial he testified that she was under the influence of marijuana and was incapable of safe driving at the time she was operating the motor vehicle. Although the trial court allowed the officer to explain why he believed the driver, Gonzales, was under the influence of marijuana, the officer's testimony was not supported by substantial evidence. The officer testified that red eyes and body tremors were symptoms shared between marijuana and alcohol, but he did not administer a breath test for alcohol to defendant Gonzalez. A blood test for alcohol was performed, but was never introduced in evidence. Why did the appellate court reverse the defendant's conviction for driving under the influence of a drug when the police officer testified concerning his observations? Explain.

Question 23

In Bowling v. State, a police officer investigated a boater for the possibility that he might be boating under the influence of a substance. The officer noticed an odor of alcohol on the breath of the defendant and asked the defendant to perform some diagnostic tests to determine whether he was under the influence of alcohol. The officer performed some field tests, and the boater did not want to do some tests. At the trial the officer was permitted to express an opinion concerning whether the boater was a less safe boater in his condition. Is a police officer a lay witness for this purpose? Did the court think the officer was qualified as an expert in detecting a drinking driver and to offer an opinion that his driving skills were impaired?

Question 24

In United States v. Delatorre, a case involving alleged drug trafficking by Mexican-American individuals, a government witness was permitted to explain some language used in intercepted phone calls and in notebooks recovered from some of the defendants. The expert witness explained what coded words meant and how the words were used to indicate what drug was being discussed. According to the reviewing court, did the trial court commit reversible error when it allowed the woman expert to explain the meanings of some of the coded words and to further explain how drug cartels typically operate?

Question 25

The general rule of evidence relating to opinion testimony is that:

A) opinion testimony of a non-expert witness is never authorized.
B) testimony relating to opinions, inferences, impressions, and conclusions drawn from facts is admissible to the same extent as testimony relating to facts.
C) the principles relating to lay witness (non-expert) testimony are the same as those concerning expert witness testimony.
D) opinion testimony of witnesses must be confined to statements of concrete facts within their own knowledge, observations, and recollection.

Question 26

Courts and legislatures have approved exceptions to the opinion evidence rule. These rules of exception:

A) are the same for expert and non-expert witnesses.
B) are applied to expert witnesses but not to non-expert witnesses.
C) have developed along two lines: one set of rules for experts and one set of rules for non-experts.
D) are so few that they have little influence on evidence.

Question 27

The traditional evidence rule is that a non-expert, or lay witness, may state a relevant opinion if:

A) the opinion is based on facts that he or she has observed.
B) the opinion is of the kind that normal persons form constantly and correctly.
C) the witness cannot adequately or accurately describe the facts on which his or her opinion is based.
D) all of the above, if other requirements have been met.

Question 28

A non-expert, or lay witness, is one who is not particularly skilled, learned, or experienced in the particular area that is at issue in the court, may have knowledge that an average person possesses, and may testify concerning:

A) cause of an accident resulting in a death.
B) the color of a car involved in a hit and run accident.
C) the blood alcohol content of an impaired driver.
D) whether a particular white powder contained cocaine.

Question 29

In answer to a question, a witness stated, "The way the man was acting at the time appeared to be irrational." This is:

A) admissible because it is a factual description of an outward manifestation drawn from observed facts under circumstances when the witness cannot adequately describe the facts.
B) inadmissible because it is pure opinion evidence and does not come within any of the exceptions.
C) admissible only if the witness is an expert witness, but not if he or she is a non-expert witness.
D) incompetent and inadmissible, because the condition of the man could be easily described by stating pure facts.

Question 30

In answer to a question, a college-aged witness stated, "The woman appeared to be intoxicated." This is:

A) admissible as opinion evidence because a description of an intoxicated person covers situations where lay witnesses may be able to offer an opinion.
B) inadmissible because it is pure opinion evidence and a college-aged individual does not have a basis on which to form an opinion concerning the level of intoxication of a person.
C) admissible only if the college-aged witness is an expert witness, but not if he or she is a non-expert witness.
D) incompetent because the condition of the man could be easily described by the college-aged student by relating actual facts and omitting any opinion.

Question 31

Sally Winchell worked as an administrative assistant for her boss and had observed him sign his signature on documents for a period in excess of five years. In order to authenticate that contained allegedly the boss' signature, the prosecutor wanted Sally Winchell to offer an opinion considering whether the given signature was that of her boss. Under the circumstances, Sally Winchell:

A) cannot testify in court considering the identity of the signature because that activity constitutes an opinion for which an expert witness is required.
B) will not be permitted to offer an opinion concerning the genuine quality of her boss' signature because she has not observed her boss making the signature for a sufficient length of time.
C) should be allowed by the trial judge to offer her personal opinion concerning the genuine quality of the signature, which was allegedly made by her boss, because she has a basis for offering her opinion.
D) should be permitted to offer her personal opinion about her boss' signature because both lay and expert witnesses are always qualified to offer opinions concerning handwriting of other persons.

Question 32

Some conditions or situations are usually considered proper subjects for non-expert opinions because of their nature. One that is not of this type and be a fact, not an opinion, would be:

A) intoxication.
B) number and name of a street.
C) sanity or mental condition.
D) speed of a car.

Question 33

To warrant the use of expert testimony, two elements are required. One of these is:

A) the subject of the inference must be so distinctly related to some science, profession, business, or occupation as to be beyond the knowledge of the average person.
B) the expert must be one who is well-educated at a college or university, such as a physician or a scientist.
C) the jury must find that a witness has observed the original facts of the case.
D) the expert must be able to give an opinion with absolute certainty.

Question 34

Rule 706 of the Federal Rules of Evidence relates to the appointment and compensation of expert witnesses. It provides that:

A) the court may appoint expert witnesses only if one party submits a recommendation.
B) the court may appoint expert witnesses agreed upon by the parties, and may appoint expert witnesses of its own selection.
C) if the court appoints its own expert witnesses, this act may not be disclosed to the jury.
D) an expert witness appointed by the court shall not be subject to cross-examination

Question 35

In selecting expert witnesses:

A) the court may not select a witness as an expert unless the witness has a degree or license.
B) under no conditions and in no jurisdictions may the judge on his or her own motion appoint an expert witness.
C) the expert is appointed without any preliminary questions by the opposing party because this would be prejudicial.
D) it is incumbent upon the party offering the witness to show that the witness possesses the necessary learning, knowledge, skills, or practical experience to enable him or her to give opinion testimony.

Question 36

When expert testimony is presented to the jury:

A) such testimony of the expert cannot be based on his or her own personal knowledge or observations.
B) as in the case of non-expert witnesses, hypothetical questions cannot be asked.
C) testimony of the expert witness may be based on a hypothetical question addressed to him or her.
D) the expert may not base his or her opinion partly on facts of his or her own observation and partly on factual evidence of other witnesses presented hypothetically.

Question 37

Federal and state statutes, as well as court decisions, include rules concerning cross?examination of expert witnesses. Among those are:

A) Federal Rule 705, which provides that the witness may not be required to disclose underlying facts on cross-examination.
B) When a witness qualifies as an expert, the witness may not be cross-examined concerning his or her knowledge of publications in the field.
C) If the expert witness is unable to recall the basis of his or her opinion, the opinion is inadmissible.
D) An expert witness who bases an opinion to a significant degree on his or her readings may be cross-examined as to that opinion by reference to other reputable works in the field.

Question 38

There are numerous areas and subjects of expert testimony, some more important than others in law enforcement. Indicate the subject or area listed that is not the subject of expert testimony:

A) handwriting of suspect observed at the scene
B) identity of suspect observed at the scene
C) polygraph examination results
D) evidence that a document was typed on a particular type of machine

Question 39

In State v. Gonzalez, the New Mexico defendant had been charged with operating a motor vehicle under the influence of marijuana. A police officer concluded that the defendant was under the influence of marijuana because of some external indications involving bloodshot and watery eyes. The defendant had admitted smoking marijuana at some non-described time in the immediate past. Although a blood test was performed, the results were never admitted in court against the defendant. The reviewing court:

A) reversed the driver's conviction for operating under the influence of a drug because the police officer would have been unable to have determined the extent of her impairment merely by looking at the defendant and by talking with her.
B) reversed the driver's conviction for operating a motor vehicle under the influence of a drug because the police officer was not qualified as an expert witness to smell and recognize the odor of marijuana.
C) upheld the conviction on the theory that the trial court made a proper ruling allowing the officer to testify that the defendant was under the influence of marijuana because the officer had prior experience with drugs and could recognize the smell and appearance of marijuana, such as to allow him to determine whether the defendant driver was impaired by marijuana use.
D) upheld the conviction because any lay person can evaluate the extent of marijuana intoxication by looking at a person under the influence of the drug.

Question 40

In the case of Bowling v. State, a police officer with the Georgia Department of natural resources observed the defendant operating his motorboat without displaying the proper lighting after dark. The trained officer conducted a safety inspection during which time the defendant, Bowling, began to exhibit some signs of intoxication or at least some signs of alcohol impairment. The officer performed some diagnostic tests designed to discern alcohol impairment, which indicated that the defendant may have been a less safe boat operator because of alcohol consumption. At the trial for driving a boat while under the influence of alcohol, the officer was permitted to give an opinion that the officer believed the defendant, because of his alcohol consumption, was a less safe boat operator and that he was impaired. While the general rule is that only expert witnesses may give opinions, in this case:

A) the officer was properly permitted to offer an opinion concerning alcohol impairment and intoxication of defendant Bowling because lay witnesses commonly form opinions concerning alcohol impairment observed in other human beings.
B) the officer properly gave an opinion at trial based on the officer's status as an expert witness concerning intoxication due to extensive training as a police officer.
C) the officer should not have been permitted to express an opinion concerning alcohol impairment because only expert witnesses may be permitted to render opinions, and lay witnesses must refrain from giving opinions in scientific matters.
D) no opinion concerning lack of sobriety should have been permitted because the officer conducted field sobriety tests on water rather than on land and could have obtained erroneous conclusions.

Question 41

The defendant in the case of United States v. Delatorre was convicted of drug-trafficking offenses. On appeal, one of the defendants claimed that the district court abused its discretion in allowing a DEA officer to testify as an expert witness with expertise on Mexican drug dealers. The court decided that:

A) law enforcement officers may not testify as expert witnesses because they lack specific training.
B) the testimony of expert witnesses is not subject to review by a court of appeals.
C) the expert testimony of a law enforcement officer is admissible if the officer is qualified and the testimony will assist the trier of fact to understand the evidence or to determine a fact in issue.
D) testimony as both an eyewitness and an expert is not permissible.