Reference Citation: Schiro, G. Forensic Science and Crime Scene Investigation: Past, Present, and Future. American Lawman, Spring 2000.


Forensic Science and Crime Scene Investigation: Past, Present, and Future


George Schiro, MS, F-ABC

E-mail: Gjschiro@cs.com

(337) 322-2724


With the 21st century looming on the horizon, I thought this would be a good time to review just how far we have come in terms of forensic science and crime scene investigation during the 1900s, and to look where we are headed in the future. Great advances in police science have occurred from 1900-1999. Many of these advancements are taken for granted these days, but imagine the challenges faced by crime scene investigators 50 or more years ago. The law enforcement agencies of the past did not have routine access to the amount information that can be gathered and analyzed from a crime scene. Today's crime scene investigation "tools of the trade" range from the downright boring to the technologically astounding, but they have all greatly impacted how evidence is collected, documented, and analyzed.

One of the most under-appreciated, yet most important, developments in crime scene investigation is inexpensively, mass-produced protective gloves. Since personal safety is of the utmost importance at a crime scene, widely available protective gloves have provided affordable protection to anyone at a crime scene. These gloves are the first line of defense in protecting the crime scene investigator and his or her family from biohazards, such as HIV and the much more infectious Hepatitis viruses, that can be found at the crime scene. Protective gloves and their use probably won't change much in the future, but other protective gear might become cheaper and more widely utilized in up coming years. This could come about as a result of new biohazards that might evolve or stricter regulation of crime scene investigations.

Another great advancement in crime scene investigation has been the easy accessibility of tools to document the scene. Today, 35mm cameras and automated color film processing are so inexpensive and widely available that, with the proper training, any agency can thoroughly and properly document evidence in a timely manner. Documentation of the crime scene visually preserves the evidence so that it can be presented to attorneys or juries many years after the crime has actually been committed.

In the past 20 years, video cameras have also become popular for documenting evidence at the crime scene. The video provides a different perspective that complements the crime scene photos and is another permanent, archival method for documenting the scene. The future will bring more widespread use of digital photography and videography. Eventually the use of film will probably be replaced by high resolution, affordable digital technology, but currently affordable digital resolution cannot compete with the inexpensive high resolution of 25-100 ISO film.

The fingerprint, pa1mprint, or footprint is still the best evidence for placing an individual at a crime scene. Individualization potential of fingerprints was recognized in the 19th century, but the practical applications of this information has only been realized in the last 20 years with the advent of the Automated Fingerprint Identification System (AFIS). AFIS can automatically compare a latent print from a crime scene to a databank of known fingerprints in a short period of time. I am sure there are some readers who remember the pre-AFIS days of manual fingerprint searches and the amount of time consumed in finding a latent match to a suspect. Today, someone enters the information on a terminal and the computer does the rest.

Another ingenious advancement in the area of fingerprints was the development of the magnetic fingerprint brush. Herbert MacDonnell, whom some of you might recognize as the father of modem day blood spatter analysis, invented this simple device that uses a magnet in the end of a small wand. The wand is dipped into magnetic fingerprint powder. The powder adheres to the wand. The powder can then be brushed onto the print without any mechanical contact between the wand and the print. There is no danger of brushing the print away and because it is controlled so well, there is little danger of overdeveloping the print. It is almost the perfect tool for developing fingerprints at a crime scene.

I see great things for the future of fingerprint technology. I think AFIS systems will one day routinely include palmprints. Crime scene investigators know that latent palmprints are routinely encountered at crime scenes, but without reference palmprints from a suspect, the information has no immediate investigative potential. I also foresee the day when latent prints developed at a crime scene will routinely be digitally photographed and entered directly into AFIS from the crime scene via a palm-top computer and a cell phone. Imagine the possibility of instantly getting a suspect's name and address while the investigators are still processing the crime scene.

Identification by DNA analysis is to the 20th century what fingerprints were to the 19th century. DNA analysis has revolutionized how blood and body fluids from the most violent crimes are analyzed and used for investigative information. DNA analysis wasn't even part of forensic science 20 years ago. Back then, ABO blood types and other genetic markers were used to analyze blood and body fluids. This analysis required a relatively large amount of bloodstain and these genetic markers were susceptible to environmental degradation. Today, a bloodstain the size of a pinhead can be analyzed using Polymerase Chain Reaction (PCR) technology invented by Kary Mullis. His invention was so revolutionary that he won a Nobel Prize. Since DNA is a very stable molecule, old and degraded blood and body fluid stains can be accurately typed. By analyzing a combination of sites on the DNA, a blood or body fluid stain can be linked back to a suspect or victim with a high degree of probability. All of these factors make DNA data ideal to be databanked.

As with AFIS, a DNA profile from a blood or body fluid stain associated with a crime can be compared to a database of DNA profiles. Some states are currently collecting DNA samples from convicted sexual offenders. The DNA data generated is stored in a databank and DNA data generated from unsolved crime scene samples can be compared to the databank. Several states are routinely making "hits" from unsolved cases to these sex offenders. The states that currently have their databanks operational can even search the databanks in the other states.

The future of DNA technology holds much promise. One day, every state in the United States and other countries that databank DNA samples will probably be connected in an international network that will leave very few rocks under which violent criminals can hide. One day, DNA analysis might also be conducted at the crime scene by using hand-held DNA analyzers. The data generated would then be sent to the databank using a palm-top computer and a cell phone. Hand-held DNA analyzers are already a reality; however, they have a long way to go before they will ever be found near a crime scene.

These are just a few examples of how far we have come, and in what direction we are going in forensic science and crime scene investigation. In order to realize the full potential of forensic science and crime scene investigation, crime labs and law enforcement agencies must be provided with the necessary resources and funds to access and implement the available technology. Only then will the future visions of crime scene investigation and forensic science be attainable.