Working With Forensic Expert Witnesses: A Litigator’s Guide

If you have a case involving forensic science (see an overview from the National Institute of Justice), it’s a good idea to hire a forensic expert witness. However, before you go out and hire the first forensic scientist you find in the relevant field, consider why you are hiring a forensic expert witness. Reasons to hire a forensic expert include the following:

1. Gathering background information about the forensic science in general
2. Observing testing performed by another forensic scientist
3. Reviewing work already performed by an expert for the other side
4. Providing independent testing
5. Observing or reviewing deposition or trial testimony
6. Providing deposition or trial testimony

In some cases, you may choose to hire an expert to perform a combination of these functions. However, these decisions must be made after considering how this may benefit your position, or whether it could be to your detriment.

Case Hypothetical

Imagine a case, either criminal or civil, which includes the following facts:

1. A person shot to death “at close range” (see NIST on gunshot residue)
2. A shotgun which may have both fingerprints and DNA on it, possibly belonging to the shooter
3. The body discovered in a house that has burned, where the fire may have been intentional or accidental

Background Information

Particularly if you have never had exposure to a given forensic science before, it might be a good idea to retain a forensic expert for background information. Consider, for example, our hypothetical. Which areas of the gun might be best to examine for fingerprints (see FBI Latent Prints or NIST on friction ridge examination)? Are some areas of the gun more likely to yield a DNA profile (see ISFG)? Can you lift a print and then test for DNA evidence (see OSAC Biology/DNA), or should you do it the other way around?

By consulting a forensic expert, you can gain general background information which may provide insight on how to proceed with testing, or alternatively, may provide information on whether the testing was done appropriately in your case.

Observing Testing

Observing testing done by the other side is a double-edged sword. On the positive side, people tend to be a bit more careful when they know they are being observed. If an analyst misses a step or does something in error, an observing expert may say something to stop the error. Additionally, if an analyst makes a mistake, the observer will see this and document it.

On the negative side, if the testing expert does everything right, sending your own expert to observe the testing renders them a witness the other side may call to confirm the original testing was conducted properly.

When considering retaining an observing witness, some ground rules should be established ahead of time. If the observer views a possible error (such as failing to change gloves between handling pieces of evidence for DNA testing), does the observing expert stop the testing and say something? Or are they only allowed to stand and watch without offering input regardless of whether some valuable evidence might be lost? Additionally, a discussion about whether the other side might be able to call the witness to testify should occur prior to observing testing. Where DNA testing is involved, consider applicable guidance (e.g., SWGDAM).

Services Provided by Forensic Expert Witnesses

• Background research and literature review
• Expert witness testimony
• Independent testing and analysis (e.g., DNA, firearms and toolmarks, fire debris)
• Case file review and second opinions
• On-site observation of testing
• Consultation on evidence handling and strategy
• Deposition and trial preparation
• Distance determination and ballistics pattern analysis
• Fire origin and cause analysis
• DNA data interpretation and statistical review

Reviewing Another’s Work

Scientists take the view if it isn’t written down, it didn’t happen. Thus, when scientists perform scientific testing, they document their work (see National Academies, Strengthening Forensic Science). An arson investigator documents the scene, including the floor plan of the home, potential points of origin for the fire, and other relevant factors (see ATF Fire Research Laboratory). DNA scientists and fingerprint experts will draw sketches or photograph the firearm, noting where relevant evidence was observed or collected (see OSAC Firearms/Toolmarks). A medical examiner takes copious notes, runs lab tests, and photographs the body (see the National Association of Medical Examiners).

Sometimes it makes sense to hire an expert to review the work of another forensic scientist. From the collection of evidence at the scene to laboratory testing to conclusions based on the evidence, every step of a scientists’ approach is subject to evaluation, and possible criticism. In many cases, a lawyer can send the evidence to a consulting forensic science expert without disclosing the expert’s identity, or even that an expert is reviewing the file. Sometimes, however, the situation requires disclosure of an expert. For example, if a medical examiner creates laboratory slides, the expert may need to go to the medical examiner’s office to view the slides in person. In those cases, again, consideration should be given to a discussion wherein both sides agree the consulting expert will not be called by the opposing party as a witness for that side.

Independent Testing

Retesting

There are two types of independent testing. First, a lawyer may wish to retest the evidence already tested. Second, the lawyer may wish to perform different testing than that performed by an expert for the other side. Particularly with DNA evidence, lawyers often find retesting the evidence a tempting approach. However, a consultation with an expert may dissuade the lawyer. This is because of the nature of DNA evidence (see PCAST 2016 report).

First, DNA is deposited on a sample now in question – for our case, let’s say it’s the shotgun, with presumed DNA from the shooter on the gun. If one side tests the gun and finds a male DNA profile matching an accused, scientists will tell you the DNA is explained in one of three ways:

1. The accused deposited the DNA found
2. The accused’s DNA somehow contaminated the gun sample at some point, either during collection, processing, or testing
3. A coincidental match explains the evidence (often discussed in terms of random match probability)

Retesting the gun will not provide any information about which of these three scenarios is correct. Instead, it will only confirm the presence of the DNA on the gun sample. On the other hand, evaluating the raw data and the conclusion the DNA matches the accused may yield a different result (see National Academies on forensic DNA evaluation and NIST on DNA mixture interpretation). In this type of case, retesting may not be the best use of funds.

New Testing

On the other hand, in some cases, lawyers seek the answer to a different question. For example, one side may examine the shotgun and determine, based on an analysis of the firing pin and test fires, the shotgun likely fired a certain cartridge casing (see AFTE). However, imagine the other side wants to know the distance between the deceased and the fired gun (see NIJ on firearms and toolmarks). Perhaps the accused shooter tells a version of events in which he shot in self-defense. Perhaps the shooter and other witnesses claim the deceased was approaching him with a knife. An attorney may request an expert determine the width of the pellet spray at 2 feet, 4 feet, 6 feet, etc. By comparing the width of the fatal wound to the width of the test fired pellet spray, an expert may determine the distance between the shooter and the deceased.

Observing Testimony

Whether during a deposition or testimony at a hearing or trial, there is some merit to hiring a forensic expert to observe the testimony. Just as when observed while testing, people tend to exercise more care, and choose words more precisely when observed. Attorneys may also benefit from hiring an expert to review previously given testimony. The expert provides insight regarding where an expert may have glossed over a favorable theory or failed to mention an important study. An expert can also assist in developing lines of testimony to advance the theory of the attorney (see FRCP 30 for depositions).

Testifying Experts

Finally, an attorney may decide to hire a forensic expert to testify. Just as with other witnesses, forensic experts are not all created equal when it comes to testifying skills. When hiring a testifying expert, look for someone who is a teacher. Attorneys should look for a forensic expert who can translate complex scientific issues into words lay people can understand. A testifying expert should be confident without being condescending. They should teach without droning on and on. They should make their points using data, photos, and graphs where these are helpful to the jury (and be qualified under Rule 702).

Determining Appropriate Experts For A Case

Sometimes, even after careful consideration, attorneys may find themselves uncertain about the appropriate type of expert. In this case, an open discussion with potential expert witnesses can assist in clarifying the issues (see AAAS Forensic Science Assessments for additional context).
Unlike medical bills or lost wages, the pain and suffering of a person cannot always be easily identified. Additionally, compensation for pain and suffering is not necessarily meant to make the person whole. That does not mean such damages are not warranted. To the contrary, pain and suffering constitutes an important component of damages calculations and is clearly allowable under tort law.

What is “Pain and Suffering”?

Generally, in the legal context, there are two types of pain and suffering that can stem from an injury—physical pain and mental anguish. Physical pain is connected to the pain of the actual injury, i.e., a chronic pinched nerve from a car accident. Mental pain and suffering refer to issues such as mental anguish and illness, emotional distress, psychological disorders, and loss of enjoyment of life, i.e., flashbacks from a serious car accident causing acute stress disorder or post-traumatic stress disorder every time the plaintiff attempts to drive.

The two types of pain and suffering are often intertwined. The physical pain from an injury, especially a permanent and/or severe injury such as paralysis or disfigurement, can understandably cause serious mental and emotional suffering. At the same time, mental stress can also manifest itself in physical symptoms such as sleep disturbances, heart palpitations, and a host of other illnesses.

The exact amount of pain experienced by a human being is a specific and individualized assessment based on biological, psychological, cognitive, and social factors. There are no simple guidelines chart; oftentimes, damages for pain and suffering are left for the juries to determine based on common sense and fairness.

What Kinds of Experts Can Establish Pain and Suffering?

Despite the subjectivity of what constitutes pain and suffering, expert witnesses are a critical aspect of establishing such damages. As a general matter, damages experts are critical in quantifying the value of the harm caused and determining the monetary amount that should be awarded to the plaintiff. In many cases, damages experts are used to explain the plaintiff’s losses by breaking down the amounts sought, such compensatory damages, lost earnings, medical expenses, as well as estimated future losses. However, damages experts are not just valuable for economic damages. They can be equally useful for establishing the monetary worth of pain and suffering.

First, the root cause of the pain should be established in order to determine its severity and permanency. Medical experts well versed in the relevant practice areas and treatment of the injuries at issue should be able to establish the present and future pain of the plaintiff. A qualified medical expert should be able to testify, to a reasonable degree of medical certainty, whether pain exists, to what extent, and for how long. Such testimony can help set the general parameters of the injury.

Secondly, pain management experts can be useful witnesses in order to establish not just plaintiff’s present and future pain but also the curative measures that plaintiff will need to undergo in order to manage it. A plaintiff that will need pain-relieving opioid medication or physical therapy for their entire life is an important factor to establish.

As to mental anguish, psychology experts can help explain the plaintiff’s psychological or emotional issues to a jury. Particularly because mental illness or suffering is an “unseen” pain, a psychologist or psychiatrist is extremely valuable in helping the jury understand the significance of such an injury.

How Much is Pain and Suffering Worth?

It is both common sense and judicial fairness that as the severity and permanency of an injury increases, so should the monetary amount for pain and suffering. It is easy to see how, as a result of a car accident, a paraplegic would receive more in damages than a person who suffered a broken (but fixable) bone. But that does not mean that the calculation of pain and suffering damages is a random shot in the dark.

Insurance adjusters, often the first line of defense in a tort action, calculate settlement offers by using the multiple method. This method takes the total of economic damages and multiplies it by a certain number in order to determine a fair amount for pain and suffering. For example, if a plaintiff suffers from injuries that resulted in a $5,000 medical bill and $2,000 in lost wages, her total economic damages would be $7,000. That total number of $7,000 may use a multiplier of 1 ($7,000) or perhaps 5 ($35,000) to determine the pain and suffering amount.

The actual number used as a multiplier is based on a number of factors. The injury itself is, of course, a predominant factor. Temporary injuries, such as bruising or other soft tissue injuries, will not yield a large multiplier like a more severe or permanent injury would. Likewise, a plaintiff that is partially liable for their own injuries decreases the chances of a high multiplier. Importantly, when calculating using the multiple method, the venue of the action is also considered. If the plaintiff filed suit in a venue that is known for high jury verdicts, the multiplier will be a higher number because the insurance adjuster will be more motivated to settle out of court.

Another method referred to as “per diem” can be used to calculate damages. The per diem method places a value on each day that the plaintiff is recovering or suffering from the incident. For example, if a plaintiff is out of work for five days and takes that time to reach full medical improvement, the per diem amount would be something deemed reasonable in light of the circumstances. In such an example, if the amount is determined to be $100 per day, then the plaintiff would be awarded $500 in pain and suffering damages.

Overall, there are a variety of ways that pain and suffering damages can be established and calculated. Due to their subjective nature, it may be easy for a jury to run askew. That is why experts that can help calculate what seems like an unquantifiable issue are critical.