In the old days crime scene clues and forensic analysis was simple. Sherlock Holmes would review the clues, analyze the evidence and simply proclaim, "It's elementary my dear Watson." In the twenty-first century, however, it is not quite that simple. Improvement in evidence identification, collection and storage methods along with advanced technologies for the analysis of all categories of evidence have made the modern CSI lab much more than a two man team of Holmes & Watson.
Not Sherlock's Lab Anymore
Computerization of data, digital imaging, advanced audio analysis methods along with advanced equipment for chemical analysis of trace evidence and the obvious advances in fingerprint analysis, DNA analysis, etc. have made the modern crime lab a complex scene where no one individual is expert in all areas of analysis.
Holmes' method of deductive analysis centered, in part, on the analysis of trifles. Small, seemingly insignificant pieces of information found at the crime. Today these trifles might include paint chips, a fragment of glass from a broken vase, a discarded beer bottle, hair or bodily fluids. In the modern day lab these are, of course, considered trace evidence and a great deal of analytical effort is expended in an effort to unlock what clues exist in the trifles.
The Forensic Lab Case Load
A common misconception, thanks in large part to the plethora of CSI type television programs, is that the crime lab spends all day investigating evidence from homicide scenes. In reality a large percentage of the labs time is devoted to investigating the evidence from drug offenses, break-ins, vehicle accidents and arsons. While the homicides grab the headlines and a spot on the nightly news at 6 and 11, making valid conclusions from the evidence at a drug bust or a robbery at the local 7-11 store is just as important when it comes to obtaining a conviction.
The Forensic Lab Team
While Holmes and Watson managed to solve their crimes single handedly, modern forensic investigation requires a team approach building on the expertise of a number of individuals. Technology has advanced to the point where no one can be an expert in all areas. Chemists, toxicologists, computer experts, forensic pathologists, medical examiners, entomologists, audio experts and forensic anthropologists among others may be part of the team.
An important element to remember in all forensic analysis is that forensic evidence by itself never proves anything. On the contrary, it may often disprove that something might have occurred or that a person of interest was not really involved.
The Lab Techs Specialize
Forensic chemists must be versed in running a wide variety of analysis and analytical equipment. From simple test tube tests (wet chemistry) to gas chromatography, infrared spectroscopy, HPLC and mass spectrometry the well-equipped lab will have several technicians each expert in some, but not all of these methods. Technicians versed in light, phase and scanning electron microscopy are required in the analysis of some forms of trace analysis. Fingerprint collection and evaluation experts are always required at the scene of the crime and in the lab where prints must be carefully and accurately lifted from a wide array of surface such as a crushed soft drink can after it has been superglue fumed.
When poisoning is suspected or involved in a crime the forensic toxicologist analyzes the evidence extracted from the victim's blood or urine. They may also be involved in identifying substances found at the crime scene or verifying drugs obtained in a drug raid.
If the crime scene involves a buried, decomposing body or skeletal remains then a forensic anthropologist and forensic odontologist (dentist) may be called into the investigation team. An expert in hair and fibers is usually required to analyze remains of clothing at this type of scene. Fiber analysis of materials takes from a crime scene is very often a critical piece of evidence that can lead investigators in the right direction. Trace fibers found on a victim, in the trunk of a car, or on a rug may be able to link a particular individual to the crime.
In cases of abductions where ransom is involved the forensic audio expert can evaluate recording of ransom messages. Sophisticated software programs are available to allow background noise to be filtered out or more often, to be amplified. Careful analysis of background sound may identity such things as a church bell ringing in the distance, a passing train, low flying plane or even children playing on a school playground at recess. All of this type information essential to help hone in on a location where the victim might be being held.
And then, of course, there is DNA
There must be DNA evidence because we see it all the time on CSI Miami, right? Well in reality there is not always DNA evidence or if it is present it may be compromised by environmental conditions or heavy contamination rendering it useless. The DNA analysis lab has moved to the forefront in most crime labs but even here it is often not possible for one individual to be expert in all forms of DNA Analysis.
The most recent item added to the DNA analysis menu is Touch DNA. Actually this has been around since the beginning but has gained mainstream attention is such high profile cases as the murder of six-year-old JonBennet Ramsey in 1966. Touch DNA occurs when someone touches something else. That something could be a piece of paper, a weapon, a victim or in the case of the Ramsey girl the waist band of her clothing. Upon the touch a small quantity of skin cells are left behind. These cells are not part of a stain or blood spot but rather simply intact skin cells left behind because your skin constantly replaces itself. These cells cannot be seen but are present at the touch site. Scrapping the area with a sharp scalpel removes the cells and then DNA can be extracted and analyzed from the sample. The DNA lab technician must keep abreast of all of these developments in this rapidly expanding area of forensic science.
In future years developing technology will add more and more to the methods and equipment available to the CSI lab and will require more and more specialization of individual members of the forensic lab team.
