The Importance of Standards
in Forensic Science

(The following article is reprinted from Standardization News, April 1995, Volume 23, Number 4.  American Society for Testing and Materials, 1916 Race Street, Philadelphia, PA 19103.)


While crossing the street, a woman is struck by a speeding car that leaves the scene of the accident. The woman expires at the scene, a quiet street in a residential area. Crime scene technicians collect the physical evidence left by the car after the collision while the only eyewitness is interviewed. The eyewitness states that he is unsure of the make and model of the car but thinks that �it was blue�. Broken glass and pieces of plastic are gathered from the roadside and paint chips are found on the victim's clothing.

The driver of the car is eventually identified as a suspect in the hit and run. In addition to a broken headlamp and a cracked front plastic grill, the car has very small bloodstains visible on the hood. The last piece of evidence collected is a fabric impression from the woman's garment that was transferred to the car's rubber bumper. The physical evidence is the only link placing the vehicle at the crime scene and the forensic scientists' testimony ultimately convinces the jury of the driver's guilt.

Forensic scientists labor in the laboratory and in the courtroom. They carefully examine the evidence, perform the appropriate analysis and render an opinion based on their conclusion. Every forensic scientist is aware of the responsibility stemming from playing an important role in determining the fate of an individual based on their testimony. This feeling is tempered by their faith in the scientific method and the scientific principles utilized to reach their conclusion.

The Evolution of Forensic Science as a Profession

Legal medicine was the term used for the application of medical knowledge to the investigation of crime. The Chinese book Hsi Duan Yu (The Washing Away of Wrongs), which appeared in 1248, provided the first association of medicine and law [1]. The book offered useful advice, such as distinguishing drowning (water in the lungs) and strangulation (pressure marks on the throat and damaged cartilage in the neck) from death by natural causes. The first appearance of experts in the courtroom was documented around the end of the 18th century [1]. The emergence of modern chemistry as a bona fide science around that period led to discoveries which were applicable to crime investigation and detection.

One of the first celebrated cases in forensic science involved the 'father of toxicology', Mathieu Orfila (1787--1853), who worked in Paris and testified in an arsenic poisoning criminal trial in 1840 [2]. Orfila and others had developed a chemical test to detect arsenic, the poison of choice for the period because the symptoms, violent stomach pains and vomiting, were similar to cholera (a common disease of the times) and often went undetected. Alphonse Bertillon's (1853--1914) anthropometry (or personal identification) system using a series of body and facial measurements for individualization, developed in 1882, and Dr. Francis Galton's (1822--1911) Fingerprints, published in 1892, were pioneering contributions to the emerging field of forensic science [2].

Alexandre Lacassagne (1844--1921) has been called the founder of modern forensic science. Lacassagne spent a lifetime making contributions including the first to recognize the significance of the striations etched on a bullet extracted from a murder victim and their link to the gun from which it was fired, thus beginning the science of ballistics. He also was the first to study the relationship between an attack on a victim and the shape and configuration of bloodstains, and was first to recognize the need for adequate means of identifying criminals through a police filing system [3].

Edmond Locard's (1877--1966) exchange principle is often quoted to this day: �objects or surfaces which come into contact always exchange trace evidence� and it was he who set up the world's first forensic laboratory in France in 1910 [2].

The first crime laboratory in the U.S. was established in 1930 by the Los Angeles County Sheriff's Department [2]. The Federal Bureau of Investigation (FBI) lab was established in 1932 and in 1937 Paul Kirk (1902--1970) set up the first academic criminalistics program in the U.S. at the University of California [2].

Presently, the organizational structure of crime laboratories in the U.S. varies from state to state. Crime laboratories are usually under the jurisdiction of a local police department, the state's law enforcement agency or a federal agency. Crime laboratories also operate under medical examiner's offices, university departments, prosecutor's offices and public defender's offices. There are also many private laboratories performing forensic examinations around the country. The criteria needed to be declared an expert in a particular field of forensic science is determined by the individual judge during the trial process. The judge also determines the amount, if any, of the expert's testimony that will be allowed during that particular trial. The District of Columbia's Frye v. United States Court of Appeals ruling of 1923 [4] has been used as a guide for evidence admissibility in court.

�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, and while courts will go a long way in admitting expert testimony deduced from well--recognized scientific principle and 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� [5]

Standardization, Accreditation and Certification

In an effort to further guide the judiciary and the forensic community, several organizations have emerged. Although there are other worthy organizations devoted to the professionalization of the field, only three will be mentioned here.

ASTM Committee E--30 on Forensic Sciences was created in 1970 [6] to address the process of standardizing the methods and terminology which are particular to the field. Many good standards have been written to date and, with the rapidly advancing technology in the field, standards are continuously being updated to reflect these changes. The volunteer membership is composed of practicing forensic scientists from around the country.

The American Society of Crime Laboratory Directors (ASCLD) is an international organization composed of crime laboratory directors whose mission it is to promote �excellence through leadership in forensic science management� [7]. The American Society of Crime Laboratory Directors/Laboratory Accreditation Board (ASCLD/LAB) is a related organization which has published minimum standards for a laboratory facility and it's personnel to meet in order for the laboratory to be declared accredited by that organization. The main areas of concern are 1) physical plant 2) administrative practices (including evidence controls) 3) personnel credentials 4) examination methodology 5) quality control and 6) report writing. [7] Approximately 35 percent of the public laboratories in the U.S. and many other laboratories in other countries have undergone this voluntary accreditation process.

The American Board of Criminalistics has developed a series of examinations to certify individual forensic scientists in their particular area of expertise. The exam questions are developed by practicing forensic scientists in their area of expertise. At the present time, the individual certification process is voluntary.

The accreditation of labs and the certification of individuals is presently being addressed by the ASCLD/LAB and the ABC, respectively. The standardization of forensic analysis techniques (which includes sufficient control stages including blanks, negative controls and positive controls) has been led by ASTM Committee E--30. Although the accreditation of labs, the certification of individuals and the use of standard methods remains voluntary, the courts (judges) will come to expect these quality assurances as the number of certified labs and individuals using standard techniques continues to grow. The standardization of methods as well as the movement of crime labs toward greater autonomy are facilitated by the increased participation of academic research laboratories in the forensic sciences. Academia played an important role in the early practice of forensic science, beginning with Paul Kirk in 1937,[2] and continues to offer a means of updating the knowledge and skills of practicing forensic scientists, providing information and collaboration on the most up--to--date analytical methods as well as providing the first training for scientists interested in the profession.

Quality Assurance

ASTM Committee E--30, ASCLD/LAB and the ABC all play important roles in guiding the profession and the judiciary towards improved quality assurance. The forensic science community has been under increased scrutiny in the 90's as high profile trials, such as the State of California vs. O.J. Simpson, where verdicts hinge on physical evidence, have been widely featured and in sometimes dominate the print and television media. Although all scientists must be continually concerned with quality, the forensic science professionals have an increased moral obligation to ensure that analyses and conclusions are objective and correct. Although quality in forensic science has and will continue to be fostered by professional pride, commitment, experience and inquiring minds, there is a strong push towards formal accreditation which seeks minimum levels of competence for forensic scientists and minimum standards for procedures [8].

For example, quality assurance in Scotland has been based on four principles [9]. Firstly, all scientific facts are witnessed by at least two scientists. Secondly, the scientists have a minimum education standard (honors graduates) and minimum training period (at least two years) before they are allowed to present evidence in court. Thirdly, techniques and instruments are thoroughly tried and tested with a range of known controls. Fourthly, a program of �declared� external Quality Assurance trials is employed with �undeclared� trials to be employed in the future.

One leading campaigner for professional standards and regulations in the forensic sciences has been John E. Murdock of the Contra Costa County Criminalistics Lab [10]. Murdock and others have campaigned for the development of ethical standards for the field, the establishment of an enforceable system of quality assurance for labs and proficiency testing for individuals, the setting of guidelines for casework using established scientific methods, the guaranteeing of impartial expert testimony in the courtroom and movement of crime labs towards autonomy. As D. Helvarg says in a California Lawyer article, �Although most crime labs are associated with law enforcement, philosophically we have to stand alone� [10]


The increased media spotlight of the forensic science community in the 90's has also increased the number of students interested in the profession. Many forensic science programs are revisiting how undergraduate and graduate education should be undertaken. The applied and interdisciplinary nature of forensic science has resulted in forensic programs administered from various departments although the areas of drug analysis and trace analysis generally are focused on in chemistry departments, whereas serology/DNA and toxicology are focused on in biology departments.

Departments of Forensic Science have been included for the first time in the most recent issue of the directory of graduate research published by the American Chemical Society. Four departments of this type are listed including the program offered through the school of public health at the University of California, Berkeley, programs offered through criminal justice programs at City University of New York and Michigan State University and an independent program at the University of New Haven [11]. Recently, graduate education in 'conventional' criminalistics has been studied and a proposal made to include an apprenticeship under court--qualified criminalists [12]. The diversity of forensic science programs in the United States is highlighted in the College Blue Book, including five departments offering undergraduate degrees and one department offering a master's degree in �criminalistics�, two departments offering undergraduate degrees, six master's and one doctoral program in �forensic science�. [13]

Independent departments of forensic science administered in universities (as opposed to police agencies) reduce the potential (or perception) of partisanship. The use of forensic scientists trained in universities and utilizing standard/certified analytical methods move crime labs towards greater autonomy and minimize the impact of 'experts' for hire by the defense who may have inadequate training and/or use questionable analytical methods. The goal is impartial expert testimony in the courtroom based on the reliable scientific analysis of the evidence (preferably using a standardized method such as those proposed and under development by the ASTM).

The Current Practice of Forensic Science in U.S. Laboratories

In the April 1973 issue of Standardization News, Charles R. Kingston wrote an introductory article on �Forensic Science� [6]. New technologies have contributed a great deal to advancements in many different areas of the profession in the 22 years since that article was published, including the highly publicized and powerful technique of DNA fingerprinting introduced by Jeffreys [14].

The modern full service forensic laboratory performs some (if not all) of the following examinations: (Note: The following list does not include the services of the medical examiner, forensic anthropologists and forensic psychiatrists as they are generally not under the jurisdiction of the crime laboratory):

1) Crime scene processing

2) Analytical services Drug Analysis Trace Evidence analysis Fiber and hair comparison and analysis Paint comparison and analysis Glass comparison and analysis Fire debris and explosives analysis Gun shot residue analysis Figure(1) Tape comparison vii) Soil and building materials comparison and analysis viii) Lamp and filament examinations Figure (2)

3) Serology/ Biology services a) Serological typing Biological fluid identification and species origin antigen antibodies iii) protein and polymorphic enzymes b) DNA analysis Figure (3) i) Polymerase chain reaction (PCR) ii) Restricted fragment length polymorphism (RFLP) c) Bloodstain pattern interpretation

4) Firearms and tool mark identification a) Firearm operability b) Projectile comparison c) Casing comparison d) DRUG--FIRE automated system Figure (4) e) Gun powder pattern interpretation f) Footwear and tire impression comparison g) Tool mark identification

5) Questioned document examination 6) Toxicology a) Breath and blood alcohol analysis b) Urine analysis c) Drugs in biological fluids and tissues 7) Fingerprint and latent identification and comparisons 8) Specialized analysis a) Computer and data recovery b) Voiceprint analysis


For much of it's history, the FBI laboratory has taken on a leadership role in research and development in several areas of forensic science, including their recent pioneering effort for fired cartridge casing comparison called DRUG--FIRE. This sophisticated technology uses a traditional microscope connected to a computer workstation to collect the magnified images of fired casings in firearms identification cases. The unique microscopic characteristics imparted by the firing pin and breech face on the casing are recorded and stored in the computer's memory and catalogued into a permanent database. Confiscated weapons are routinely test fired and the resultant casings are recorded into the database.

The DRUG--FIRE software searches each image for similar topographical characteristics and a �hit list� for possible matches is generated. The added bonus to this equipment is it's ability to search databases in other jurisdictions. The State of Florida has implemented a state--wide network of DRUG--FIRE computers (see figure 4) and the preliminary results have shown a great potential for the successful association of routinely confiscated weapons with unsolved shootings (even though they might occur in different parts of the state).

The stated objective of DRUG--FIRE is to provide the means for the following: 1) promote the collection and interagency sharing of forensic data and imagery 2) rapid, comprehensive searching of local and regional firearms evidence files. overcoming jurisdictional and logistical constraints by performing remote electronic comparisons of digital images. 4) linking unsolved shootings to other shooting incidents and/or confiscated firearms. utilizing firearms evidence to link repeat offenders to crimes and expediting their identification and apprehension [15]

The FBI has also been instrumental in the creation of technical groups which regularly meet to address pressing issues in the field. The Technical Working Group on DNA Analysis Methods (TWGDAM) �was formed to address the development and implementation of forensic DNA analysis methods in public crime laboratories throughout North America� [16]. The group has published guidelines for conducting RFLP and PCR based tests for use by the crime laboratory community. (See Figure 3)

The Future of Forensic Science

Lower limits of detection of materials including drugs and accelerants at crime scenes via improved biological detection systems (primarily canine detection) will continue to enhance the investigator's set of tools in the field. Forensic scientists expect improvements in the isolation and separation of these materials recovered from crime scenes by the incorporation of new analytical methods such as supercritical fluid extraction (SFE) and solid--phase microextraction (SPME). Improved detection limits and faster confirmation of the identity of isolated materials can be obtained via increased use of new analytical instrumentation developed at government research centers and in practicing forensic science laboratories with increased collaboration with faculty at research universities.

The forensic science community anticipates an ever--increasing role of statistical methods of analysis as data banks become increasingly available on more evidentiary materials. The information age will also make these resources available to all experts more efficiently. The use of standardized methods by certified personnel in accredited laboratories will become routine as these quality assurances become expected by the courts.




1 Kind, S. and Overman, M., Science Against Crime, Aldus Books, London, U.K. 1972

2 De Forest, P.R., Gaensslen, R.E. and Lee, H.C., Forensic Science; An Introduction to Criminalistics, McGraw--Hill, New York, 1983

3 Lane, B., The Encyclopedia of Forensic Science, Headline Book Publishing, London, U.K., 1992.

4 Saferstein, R., Forensic Science Handbook, Prentice--Hall Inc., Englewood Cliffs, N.J. 1982.

5 Frye v. United States, 293 F.2d 1073 (D.C. Cir. 1923)

6 Kingston, C.R., �Forensic Science,� Standardization News, vol. 1, no. 4, pp. 1--8, 1973.

7 Laboratory Accreditation Board Manual, American Society of Crime Laboratory Directors, January 1994.

8 Davis, R.J., �Forensic Science on the Quality Track�, Journal of the Forensic Science Society, Vol. 31, No. 4, 1991, p. 407.

9 Knibb, L., �Quality Assurance in Forensic Science. QA--AQ: Quality Assurance--Answers Questions�, Analytical Proceedings, Vol. 27, 1990, pp. 280--281.

10 Helvarg, D., �Crime Labs Under the Microscope�, California Lawyer, Vol. 11, No. 12, 1991, pp. 43--105.

11 �Departments of Forensic Science� in Directory of Graduate Research, American Chemical Society, Washington, D.C., 1993.

12 Linquist, C.A., Liu, R.H., Jenkins, K. and Yates, L., �Graduate Education in 'Conventional' Criminalistics: A Proposal and Reactions�, Journal of Forensic Sciences, Vol. 39, No. 2, 1994, pp. 412--417.

13 The College Blue Book, 23rd Edition, �Degrees Offered by College and Subject,� MacMillan Publishing Co., New York, N.Y. , 1991

14 Jeffreys, A.J., Wilson, V. and Thein, S.L. �Individual Specific 'Fingerprints' of Human DNA�, Nature 316 (1985) pp. 76--79.

15 Sibert, R.W., �Drugfire: Revolutionizing Forensic Firearms Identification and Providing the Foundation for a National Firearms Identification Network�, Crime Laboratory Digest, Vol. 21, No. 4, October 1994, p. 63--67.

16 �Notes from the Technical Working Group on DNA Analysis Methods�, Crime Laboratory Digest, Vol. 21, No. 4, October 1994, p. 69--74.

(Editor --� Standards, accreditation and certification will continue to have an increased influence on all aspects of Forensic Science.  Everyone working in the field of forensic identification must be familiar with these influences, as ignorance about one's profession is not bliss!)




This article was printed in �THE PRINT�
Volume 14(5) September/October 1998, pp 3-7
and has been obtained from the online library provided by the

Southern California Association of Fingerprint Officers