Forensics | The Rules, The Scene, and The Collection Process

Forensics | The Rules, The Scene, and The Collection Process

Frye and Daubert

Law and science have always been uneasy partners. The stark differences between the two dates back to the fourteenth century. Now, in the twenty-first century, the disparities are coming into the light. The public view is changing and challenging how the legal system should continue to proceed into the future.

As forensic sciences advanced, the legal system attempted to conclude what is and is not admissible in a court of law. The first significant advancement in this partnership occurred when the Washington DC Court of Appeals issued a landmark decision in 1923 in the case of Frye v. The United States.

In 1923, James Alphonso Frye, who had been convicted of second-degree murder, appealed his conviction. He had confessed to the crime, then later recanted. A jury of his peers convicted him. The basis of his appeal was that in the original trial, he was denied the ability to introduce evidence regarding his truthfulness. The evidence he had wished to present was the results of a “systolic blood pressure deception test.” This test was the forerunner to what is now known as the lie detector test. The court had refused to allow testimony from experts to explain the concept of the test and its results.

A three-judge hearing before the Court of Appeals of the District of Columbia unanimously ruled against Frye. Their decision and remarks became one of the most prominent decisions in today’s legal system. The court ruled that the device and test had not gained enough scientific standing among the community to be considered as an appropriate standard. The court wrote this response in its decision:

“Just when a scientific principle or discovery crosses the line between the experimental and demonstrable stages is difficult to define. Somewhere in this twilight zone, the evidential force of the principle must be recognized. While the courts will go a long way in admitting experimental testimony deduced from a well-recognized scientific principle or discovery, the thing from which the deduction is made must be sufficiently established to have gained general acceptance in the particular field in which it belongs.”

This decision has come to be known as “the Frye standard” and is still followed in several states today. The states that still use this standard as a guideline in their courts today include California, Illinois, Maryland, Minnesota, New Jersey, New York, Pennsylvania, and Washington.

Other states use a combination of the Frye standard and the “Daubert standard.” The Daubert standard is similar to the Frye standard; however, it applies toward the admission of expert witness testimony. Seven members of the court have agreed on a set of guidelines for allowing witness testimony.

Defining Rule 702

The first rule of the Daubert Standard requires the trial judge to use Rule 702. What does that mean? In 1975, the Federal courts adopted litigation to be used as guidance rules in the court trials under the Federal Rules of Evidence. The Federal Rules of Evidence 702 establishes that a witness is considered a qualified expert by knowledge, skill, training, or education and may testify to the results of tests that comply with Federal guidelines under the scientific method. This rule has been updated several times in the past 45 years. As of 2020, conditions for the testimony of an expert witness under these guidelines are defined by Federal Rules of Evidence as:

  1. The expert’s scientific, technical, or other specialized knowledge will help the trier of fact to understand the evidence or to determine a fact in issue;
  2. The testimony is based on sufficient facts or data;
  3. The testimony is the product of reliable principles and methods, and
  4. The expert has reliably applied the principles and methods to the facts of the case.

Science Matters

The court rules make a difference when collecting, preserving, storing, and testing evidence. While forensic science has come a long way and helped to solve many crimes, in the last twenty years, it has come under intense scrutiny. How first responders and others in law enforcement handle the evidence, process it, and use chain-of-custody records to demonstrate the validity of the samples as they are tested and returned to the court makes a substantial difference. Going the extra distance to follow procedures, keeping immaculate records, and maintaining a clean reputation is crucial to proving cases in court.

Questionable Forensics

Through the Innocence Project, it has come to the attention of the courts and forensics scientists that faulty forensic data has led to the conviction and possible execution of innocent persons. Studies have uncovered a troubling number of wrongful convictions.

The issue is as defined above – the scientific method. The problem is that many forensic science results such as hair analysis, bite marks, or those used to infer tool marks have never passed a scientific examination. The testing techniques do offer some logic, but is it truly following the scientific method? Many times, it results from other evidence that gives the forensic scientists conviction in their reasoning. Reasoning or opinions is not science. Convictions based on false intelligence or testimony is an environment for illustrating how unethical decision making can cost lives. In other words, “Complacency Kills.”

The Gold Choice Standard

There is some urgency in learning and understanding the scientific methods involved in evidence collection and forensic testing. Not only is forensics now facing public scrutiny, but labs are dealing with scandal as many wrongful convictions have been discovered based on junk science. In 2015 the FBI demonstrated to Federal courts that hair microscopy was not based on science at all, but personal judgment. Hair analysts had come forward regarding misleading testimony that helped to wrongfully convict 33 death row inmates, of which nine had been executed, and five had died while in custody.

DNA is considered the gold choice standard. It can be scientifically tested and results given that can be verified, proven, and even retested for the same results. An important study by the U.S. Department of Justice has made the final decision that excluding DNA, no forensic evidence testing, or method has the capacity to be consistent and prove with a high degree of certainty any link between the evidence and a particular individual or source. This idea has come as a shock to most labs and forensic experts who believe in their work and subjective opinions.

Preserving the Scene

With all this confusion, how can a law enforcement officer, evidence collection specialist, or first responder be sure that the job that they are doing is helpful to solving a situation, crime, or accident? Number one, start with preserving the scene. What does that involve?

Start with a logbook. This may seem minor, but it is significant in maintaining details of the crime scene and anyone who may cross the threshold. Clear the scene and keep it clear. Anyone present, including the investigators, or evidence collection team, can contaminate the scene and the evidence available. Try to keep the numbers at a minimum. The more people that are present on the scene, the higher the chances are that the scene will become contaminated in some way.

Only essential personnel should cross police lines into the restricted areas where the crime or incident occurred. Use the logbook to take down names and department contact information for every person who crosses into the scene. Found evidence, such as a random hair, may have to be compared with others that came into the scene to eliminate them and verify the possibility that it belongs to the perpetrator.

Be awake and alert. Coming into a scene tired or off-key will not help when concentration needs to be your calling card. As a crime scene investigator, law enforcement officer, or first responder, it is important to remain hyper-vigilant regarding the scene and every component of the area. You may be called to testify regarding every detail that you see, hear, or even smell.

As an investigator, there is a significant weight of responsibility to collect everything that you find, regardless of how you feel it will be used, not used, or tested. Things that you should look for can include fingerprints, shoes, fibers, blood, saliva, hair, chemicals, clothing, tools, weapons, and more. There is nothing that you can miss because even the smallest detail, such as a tiny piece of glitter, maybe the key to resolving the crime. You’re responsible for collecting these details as well as interviewing anyone at the scene that can provide you with additional information, which can also help you look for clues. You should record everything, including non-tangible details such as the lighting, smells, any disorder, or even the conditions of the area. Any of these details may become important at a later date.

It is also important to search the surrounding areas. Covering the crime scene with meticulous detail is obvious, but clues can be left in areas surrounding the crime. Areas outside of the crime scene, such as the driveway, trash cans, alleyways, and parking lots, can also lead to additional clues. Individuals coming onto the scene must understand that these areas are also under preservation and should not enter the areas unless necessary. Crime scene preservation is an important area of responsibility, and doing it correctly can help gain the necessary evidence needed to solve the crime.

Careful Collection Processes

Evidence collection is a systematic process, much like the time taken to preserve the scene. Investigators should collect evidence methodically and carefully. As an investigator, when you first encounter a new scene, and you have established the police lines or preservation of the area, you can begin a series of judgments on how to proceed with the collection of evidence.

Before beginning to bag your proof of the crime, study the scene location, and take notes in your logbook. Is it an interior, exterior, or inside of a vehicle? What is the condition of your evidence? Is it something fragile and needs to be sampled immediately like blood or body tissue, or is it stable and can be secondary as in tools, weapons, or clothing? If you are dealing with a crime scene that is outdoors, what is the weather? How will it affect your scene as you go about your duties? Is it about to rain?

Have the scene management conditions or police lines been placed satisfactorily, and have you logged each individual that will be handling the scene with you? Is the scene clear? Another thing that may arise when handling a crime scene is that you may come across an item that requires specialized attention. One example would be a bomb or other explosive device. If something that needs a specialist to help process the scene, have they been called in? How long till they arrive?

As an investigator, you should have a standard collection kit. It may be a good idea to have more than one, so they can be ready to go in an instant. Your “toolbox” should contain sterilized equipment so as not to contaminate the scene while you collect the evidence. Things that you should have available in each toolbox to process a scene may include:

Sampling the Scene

As you collect your forensic samples, you will find that the swabbing technique is the most recommended method that forensic leaders advise. It is best used in the recovery of biological evidence, gun powder residue, and other trace evidence.

For dried material collections, using gloved hands, lightly moisten your swab with the distilled water. Thoroughly rub the stained area or sample with the tip of the swab. Each sample needs to take more than once for verification purposes. Allow the swabs to air dry. Some investigators use the longer swabs and have made a stand available to hold the swab upright while they write down the information about the collection process. Once the notes are written, the swab is generally air-dried.

Every swab should go into a separate package. When you are finished processing the crime scene, these packages or small bags with evidence can then be placed inside a large paper envelope. Be sure that for each sample obtained; there is also a control sample that is taken as well. Choosing a control sample means that once you have taken the sample of the stain, then also take a sample of the clean area next to the stain, for comparison.

It is also essential to become familiar with your department’s policies on handling other forms of evidence. They may have processes that they want you to follow. An example would be if blood-stained clothing were found, you may need to wrap with plastic wrap as the stain could be wet, and folding the clothing means there will be a significant transfer of evidence across the material. Any blood spatter would then be inconclusive. Wrapping these types of items helps to preserve the scene for the laboratories.

Setting Up Chain of Custody

Chain of custody is essential. Knowing what happens to the evidence from the scene through the police department, the laboratories, the courtrooms, and legal service providers and being able to demonstrate to the courts that evidence was handled correctly and secure every step of the way helps when it comes to admissibility standards.

CaseGuard software can help with setting up reports, chain-of-custody, and other requirements to fully take control of your evidence procedure. With document redaction software available from CaseGuard, the privacy of individuals not associated with the crime can be protected with redaction processes. The software also handles reports for evidence, chain-of-custody, records redaction histories, and can also handle all evidence room management needs.

Establish your chain-of-custody procedures while collecting the evidence at the crime scene, and it is vital to know how your agency manages inventories and packaging. The evidence itself cannot be marked, but the envelope or bag which contains the proof should be clearly labeled. Details that should be included in the evidence label are:

The chain-of-custody is a tracking document. You begin by entering detailed information regarding the scene of the crime, the evidence collected, how and where it was retrieved. Upon transferring the evidence to the property room, this chain-of-custody documentation would then be updated. It would include information such as the type of evidence, the senior officer in charge of the investigation. The information on the senior officer should consist of his name, rank, and identification number. The reason is that when tests are run through the labs, the results are then returned to the leading officer.

Information regarding the transporting officer, rank, ID number, and name if you have one. You should obtain the signature of the officer that is in charge of the evidence in the property room. It is a valid form of verification that the evidence had been received and stored. A comment section can also be included, which can give additional information about the evidence collected.

Each time the evidence is moved, a signature, ID number, and name must be recorded. It should also include the date and time of the transfer. This information should be a part of your chain-of-custody reporting. The officer releasing the evidence from the property room would sign as well as the officer or lab technician who is receiving the property. A crime scene report, as well as a statement that demonstrates a full and diligently collected chain-of-custody is necessary for courts to take evidence in the trial process as a valid form of information. Keeping quality information and attention to details will pay off with a solid reputation and a great career.

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