Crime Solving Benefits Can Be Obtained From Certain Ballistics Evidence Once Overlooked As Most Likely To Produce The Highest Probable Value.
Pete Gagliardi, FTI and Richard Leary Managing Director of Forensic Pathways.
Police operate under the assumption that there is no perfect crime, that every “contact leaves a trace”(1) therefore, every crime can in theory be solved. However, effective police work requires a continual balance of the amount of time, effort, and resources that can be applied to the investigation of a particular crime simply because resources are limited. This comes as no surprise, because as we move through our own personal lives we continually evaluate our options and make choices that are most likely to provide us with the most value.
Because of resource constraints, police are often forced to pursue only the information of highest probable value in order to realize the proverbial “most bang for the buck.” By this we mean that only evidence that is likely to produce the required result in a direct way is collected. However, every crime is different and so deciding what evidence should be recovered and is relevant can be very difficult. The recovery of evidence has been traditionally governed by deciding what is relevant. As Doyle [Sherlock Holmes] said:
It is of the highest importance in the art of detection to be able to recognise, out of a number of facts, which are incidental and which are vital. Otherwise your energy and attention must be dissipated instead of being concentrated. (2)
This acknowledged that it was a bad strategy and a poor use of resource to “ overturn every stone in the hope of finding something.”
For example, police conducting a crime scene search for evidence of the crime of breaking and entering will often begin at the point of entry and move to the point of exit (e.g. doors, windows, etc.). This is in the hope of finding something relevant to the identity of the offender. The forced door or broken window has a high potential to yield an abundance of physical evidence (e.g. broken glass, DNA, fingerprints, tool marks, etc). Following the concept of highest probable value, the crime scene investigator continually evaluates and re-evaluates how far the search for evidence will extend in terms of time, effort, and resources.
This is made even more difficult because Police must continually balance the severity and social impact of a crime with the amount of resources that can and should be applied to its investigation. The extent of the search for evidence has traditionally been arbitrary and undertaken with limited tools and a massive reliance upon the ability of the crime scene examiner to use their senses to sense the evidence of the highest probable value. Tools that enhance our ability to sense evidence have until recently been developed slowly.
While it is still true that crime scene examiners need to use their senses to sense evidence, forensic science has developed new tools and methods that enhance this ability. Even the slightest traces of material for analysis that would normally be beyond our ability to sense can now be recovered and analysed. What was once overlooked, missed or thought to be unimportant can now be ‘sensed’ and treated as possibly important. Furthermore, this evidence can now be stored in enormous databases with automated cataloguing and ‘matching engines’. Matches’ and even evidential leads can be produced routinely to such an extent that what was previously beyond us has become within our grasp. In many cases we can now literally “overturn every stone in the hope of finding something.”
Consider the field of Forensic Ballistics. The comparison of the minute markings and striations left on fired ammunition components (e.g. bullets and cartridge cases) under a comparison microscope is a very manual and tedious task. For almost 80 years it was difficult at best and perhaps impossible for some labs to sustain the comparison of every new piece of evidence recovered against their own open case file inventory. For every lab to sustain the exchange of ballistics evidence and query each other’s open case inventories looking for leads was as unheard of as human flight was to early man. But not any more: Very soon, we will truly be able to compare every item of evidence recovered with every other item of evidence in the hope of finding something….i.e. ‘matches.’
A key point of this paper is that “ things change.” Leonardo DaVinci once said that “there shall be wings – if not for me but for another . . .” Yet for centuries, many people believed that flight was impossible. Maybe the renaissance society overlooked DaVinci’s sketches as artistic expression but we wonder what the neighbors must have thought of the Wright brothers when they first began experimenting with flying machines? Today we take air travel for granted and at the same time we continue to witness new ways of doing those things that were previously thought to be impossible. Just recently, the airline industry introduced a new jumbo jet capable of carrying 800 passengers and boasting an onboard gymnasium.
Police work is no exception to the effects of advancing science. It too is changing. Take Forensic Ballistics for example. In recent years, we have witnessed automated ballistics technology go from innovation to mainstream. Ballistics information sharing networks linking hundreds of agencies and labs have been created to do what was previously thought to be impossible – access and query every open case file of evidence on the network in order to find investigative leads. Automated ballistics analysis systems can now sustain the comparison of even the seemingly insignificant pieces of evidence. Evidence that may appear to be insignificant to one agency may now prove to be the long lost case-breaker for another. Forensic Technology’s Integrated Ballistics Identification System (IBIS) is the preeminent system that is being used to create ballistics information sharing networks at the local, regional, national, and international level.
The collection of large amounts of [possibly relevant rather than definitely relevant] evidence along with the ability to identify ‘matches’ routinely has far reaching consequences. An example is a computer like IBIS that stores details on the evidence collected by investigators and crime scene experts with such accuracy and power of retrieval that cases thought long ago to be beyond solving can be solved routinely and reliably. Should we be surprised by this? We say not because one characteristic of science is its’ ability to recognise advancement and change. Many of us treat science as some form of irredeemable truth or constant that never changes whereas in reality what sets true science apart is its ability to recognise advancement and change. In modern science, what was once thought to be constant and beyond question becomes simply a challenge. In modern science the only real constant is ‘ change’ itself. This is having profound effects in forensic science and particularly ballistics.
What can we conclude from all this? Things have certainly changed with respect to how we should view forensic ballistics evidence in terms of defining highest probable value. The tide has turned. IBIS technology can correlate evidence at speeds well beyond human capability, exchange data more quickly and efficiently, and help police sustain the generation of more information than ever before to link crimes, guns, and suspects through ballistics evidence. Therefore, we submit that the highest probable value now lies in the collection, imaging, and sharing of all Forensic Ballistics evidence taken into police custody.
“Things change” and we must continually be aware of our changing environment so that we can reposition our viewpoints and seize new opportunities to be more efficient and effective at making the world a safer place.
Forensic science now allows us to examine finite detail so that we can collect more, analyse and evaluate more and draw more reliable conclusions. We can literally get even more ‘bang for our buck: As the father of reforming science Descartes said, to make so complete an enumeration of the links…and to pass them all so thoroughly under review, that I could be sure I had missed nothing. (3 )
Although effective police work requires a continual balance of the amount of time, effort, and resource that can be applied to an investigation, developments in science and technology can make us more efficient and cost effective so that we can reasonably say that given our new tools, “we have missed nothing.”
1 Edmund Locard.
2 The Adventure of the Reigate Squire: Page 373.
3 Descartes, Discourse on Method, p.36.