During the course of two sessions the Hatboro and Horsham Citizens Police Academy covered Crime Scene Investigations (CSI). Although I was unable to attend the first session, where Horsham detectives presented the framework of CSI work, do to more pressing matters. As a result, those observations come to you through the eyes of a fellow classmate, Emily Ann.
The first CSI class was led by two of Horsham’s finest, Detectives David L. Bussenger and Robert J. Waltz. The second CSI session came two weeks later, led by Montgomery County Detective Richard J. Nilsen, Jr. of the Forensic Services Unit in the Office of the District Attorney for Montgomery County, PA.
In the following description, only the names have been changed to protect the innocent …
Crime scene investigations are geared towards determining Who committed a crime by answering the questions
- What took place?
- When did it occur?
The purpose of CSI is to determine what happened and who is responsible. The ultimate goal is a proper “Guilty” verdict and punishment as set forth by the Court.
The investigative process begins with the initial police contact.
The first responding officers at any potential crime scene are responsible for rendering first aid and to summon an ambulance, if necessary. They must also note what they see, hear, and smell … Time of day, weather conditions, people and vehicles at the scene and that might leave before investigators arrive.
Responding officers must also protect the crime scene from unnecessary traffic, disturbance, or contamination. Responders will listen for what might be said by people on the scene and must separate any witnesses isolated from one another. Witnesses are separated to prevent any comparison of their version of events and – if involved – to ensure they do not rehearse their stories. All observations are then passed on to the assigned investigators.
The investigators will call upon additional specialists as needed. They include photographers, sketch artists, evidence recorders who maintain the “chain of custody” for all physical evidence, and experts from more specific fields of study … anthropologists, blood pattern analysts, and the medical examiner in cases of death.
Physical evidence is the bread and butter of law enforcement investigative work. The chain of custody for that physical evidence is crucial to successful prosecutions. Proper chain of custody allows for the identification and description of all aspects of the physical evidence months or years after its collection. The chain of custody must be protected from any contamination and preventable degradation of biological samples. For that reason, the chain of custody must be able to prove that all evidence was properly preserved and kept properly secured from tampering until presented in Court during the criminal trial.
Predictable physical changes in evidence, such as degrading tissue and blood samples cannot be entirely prevented. The potential for an investigator to cause changes in evidence through improper technique must be anticipated and prevented. Evidence recorders must be able to address anticipated changes in physical evidence (e.g. normal degeneration of blood and tissue samples) from the time the evidence is collected until it is presented in Court.
Once investigators begin processing the immense amount of data from a crime scene, it’s important that they NEVER overlook the obvious. After all evidence has been collected, photographed and sketched, and all witnesses have been interviewed, investigators will compare their initial findings to ensure all observations and individual perspectives are included.
Other considerations during an investigation:
- Physical evidence does not lie. Let it tell you what happened.
- A hypothesis developed from the evidence and interviews is an important step. But an investigator can never be afraid to change the theory especially if the physical evidence indicates a change is appropriate.
My friend, Emily Ann, described for me the highlight of that first CSI night … the crime scene adaptation presented by Detectives Bussenger and Waltz. Emily Ann described a burglary crime scene laid out for the CPA participants with an array of physical evidence, challenging questions put to the participants, and the interesting way the detectives explained how they process such a crime scene.
Emily Ann found it interesting and quite instructive to see a crime scene laid out as an investigator might find it; and learning how they would go about weaving a theory from the physical evidence documented.
This was the angle that Detective Nilsen was really able to hammer home during his presentation on the second night of CSI. He was able to provide both context and bit of visual discomfort as he provided very real and very graphic crime scene photos. (All photos were carefully taken and framed so as to not reveal any details on the specific case or any information about the victims who were portrayed.)
But first Detective Nilsen had to blow away all my preconceived notions of detective work as I have gleaned from years and years of watching CSI: Miami/Las Vegas/NYC, eight different versions of Law & Order, and a healthy dose of Criminal Minds! Apparently, most everything I have come to believe in watching detective TV is a farce, perpetrated by television’s need to fit a weeks or months-long story into 44 minutes (sans commercials).
There is no Garcia pounding furiously on a computer keyboard and able to provide everything from hat size and favorite color to the specific location and contents of last meal eaten for every crime victim, perpetrator, and key witness privy to the macabre details of any violent crime. There is no magical finger-printing system that churns through potential print matches as a detective watches, then spits out the matching perp in the time it takes to fix your mocha latte. There is no crime lab that would let a regular detective jump right in, complete with a blue Tyvek hazmat suit to twiddle around with the DNA sequencing systems and scanning electro-microscopes (unless properly certified).
Great … Now I have another 6 hours a week I’ll have to find something productive to do …
Detective Nilsen’s presentation highlighted how such crime scene evidence as blood spatters, ballistics dynamics, corpse conditions (lividity, stage of mortis, wound dynamics, etc.), transference of materials from perpetrator to victim, etc. all come together to prove the detective’s favorite adage …
Dead men DO tell tales!
My personal “wow moment” was watching the animation generated by a piece of equipment called a Scan Station, a surveying type tool that provides a 360°, computer-generated survey of any potential crime scene. The equipment is so sophisticated that once scanned a detective can visualize a crime scene from any angle (above, below, any side), even from “outside” the scene, as was proven when the class visualized a particular crime scene from outside then “flew” in through a window to view the interior of a virtual crime scene depiction.
Detective Nilsen, a former Lower Merion officer and Widener Law School graduate, also provided an in-depth look at fingerprint analysis and AFIS (Automated Fingerprint Identification System), the dynamics of projectiles (bullets), DNA and blood collection, and a case study in the arrest and conviction of Charles “Acme John” Eichinger, one of his first cases as a MontCo detective.
The most important thing I learned from these two nights of CSI …
Crime is definitely not a good long-term job choice!