The Forensic Casebook: The Science of Crime Scene Investigationby Ngaire E. Genge, N. E. Genge
An intrepid investigator crawls through miles of air conditioning ducts to capture the implicating fibers of a suspect’s wool jacket . . . A forensic entomologist discovers insects in the grill of a car and nails down a drug dealer’s precise geographical path . . . A gluttonous
THE ULTIMATE READERS’ GUIDE TO THE ART OF FORENSICS!
An intrepid investigator crawls through miles of air conditioning ducts to capture the implicating fibers of a suspect’s wool jacket . . . A forensic entomologist discovers insects in the grill of a car and nails down a drug dealer’s precise geographical path . . . A gluttonous criminal’s fingerprints are lifted from a chocolate truffle. . . .
Filled with these and many other intriguing true stories, and packed with black and white illustrations and photographs, The Forensic Casebook draws on interviews with police personnel and forensic scientists—including animal examiners, botanists, zoologists, firearms specialists, and autoposists—to uncover the vast and detailed underworkings of criminal investigation. Encyclopedic in scope, this riveting, authoritative book leaves no aspect of forensic science untouched, covering such fascinating topics as:
• Securing a crime scene
• Identifying blood splatter patterns
• Collecting fingerprints—and feet, lip, and ear prints
• Interpreting the stages of a body’s decay
• Examining hair and fiber evidence
• Trace evidence from firearms and explosives
• “Lifting” DNA prints
• Computer crime and forensic photography
• Career paths in criminal science
Lucidly written and spiked with real crime stories, The Forensic Casebook exposes the nitty gritty that other books only touch upon. Here is a reference book as addictive as a page-turning novel of suspense.
Read an Excerpt
THE SCENE OF THE CRIME
The Scene of the Crime Versus the Crime Scene
For novelists like Agatha Christie, the scene of the crime was obviousâ€”a blood-splattered drawing room or the gaping wall safe in a society grand dameâ€™s bedroom. Modern law enforcement officers, criminalists, forensic scientists, and even the often maligned private investigators, however, have quite different definitions.
The â€œscene of the crimeâ€? might be a room, an entire building, a wharf and surrounding harbor, the three-mile path of a disintegrating airplane, or just the keypad and receiver of a public phone booth. However, the actual â€œcrime scene,â€? to use the language of forensic investigation, often bears little resemblance to the physical layout visible at the scene. And, surprisingly to most, the size of the scene often has little relation to the time required to work it. For example, a phone booth regularly used by a stalker in Kingston, Australia, required eight technicians working for three full days. The first crash scene David Kellerman of the Aeronautics Investigative Unit ever worked required dozens during the rescue phase, but the actual forensic investigationâ€”due in large part to the first responderâ€™s swift creation of a single access path for rescuers, as well as to the presence of snow (which helped in locating loose debris some distance from the crash)â€”took a mere nine investigators less than two days to complete.
Of course, the physical size of the crime scene bears no relation whatsoever to the number of individuals, either suspects or witnesses involved, and, as collecting statements is as much a part of â€œworkingâ€? the crime scene as swabbing blood stains, scene size can be quite deceptive.
A nylon bag, measuring less than a foot square and four inches thick and containing nothing more than a laptop and modem, was the only physical evidence of a conspiracy involving hundreds of people and millions of dollars in a penny-stock scam. At the other extreme, the bombing of the Alfred P. Murrah Building in Oklahoma City was ultimately attributable to only a handful of people. The number of witness statements required during these investigations, however, was virtually identical.
The tiny computer bag, every bit as much a crime scene as the rubble of the Murrah Building, presented investigators with specialized problems not found at scenes requiring miles of yellow tape. The bag was mobile, its contents were subject to destruction by the simple wave of a magnet or flip of a switch, and the computer inside was the actual property of any number of suspects. The scene in Oklahoma, while horrific in its loss of life, couldnâ€™t be slipped into a pocket and hidden away from analysts.
A â€œcrime sceneâ€? isnâ€™t only the actual location of the crimeâ€”it is also the staging and planning areas, the paths of flight to and from the primary scene, and the paths between the primary and secondary scenes. Consequently, the total crime scene for a twenty-first-century offense might prove international and include dozens of physical locations and individuals, thousands of exhibits, and nearly as many witness statements.
As I prepare this manuscript, the investigation into the September 11 attacks on the Pentagon and World Trade Center and the crash in Pennsylvania, is just swinging into high gear. Already the FBI is reporting nearly 7,000 investigators and support personnel following up â€œ35,0001 leadsâ€? and looking into â€œnumerous international possibilities.â€? Cars at several airports, apartments and hotels in places as far apart as Boston, Massachusetts, and Vero Beach, Florida, are just a few of the secondary scenes being secured. Electronic scenes also could contain vital information, but such evidence could be as difficult to collect as an impression of a shoe in the snow of a sunny field.
Scenes like the Pentagon and the World Trade Center are obviously, and thankfully, the exception. But the far-reaching scope and the need to coordinate rescue efforts with forensic investigationâ€”all while maintaining a secure scene in which the lives of investigators and emergency staff arenâ€™t further endangeredâ€”makes these cases well-documented examples of the difficulties that law enforcement personnel face, even if it is usually on a smaller scale.
Crime happens everywhere, and determining what territory, items, and persons make up the â€œcrime sceneâ€? isnâ€™t always easy. Constantly confronted with the dangerous or unexpected, investigators juggle a number of imperatives in their efforts to turn the â€œscene of the crimeâ€? into a secured â€œcrime scene.â€? But, in the vast majority of cases, this is the first decision to be made in a criminal investigation, and it is often made by the first responder to the sceneâ€”not a criminalist. A mistake made at this stage can end any chance of solving the crime, let alone prosecuting the offenders.
Both the film version and the book version of Anna Porterâ€™s The Bookfair Murders begin with the crime scene investigatorâ€™s worst nightmare: a murder accomplished in the middle of 300 witnessesâ€”300 potential suspectsâ€”all of whom are due to scatter to numerous countries outside the local detectiveâ€™s jurisdiction in three days if the investigation doesnâ€™t generate enough evidence to book someone. On top of that, the Frankfurt Bookfair is a four-day event, with conference rooms and booths set up in temporary quarters through which thousands of people tramp each and every day of the show.
As the collection of evidence at the crime scene includes the names and contact informationâ€”and, hopefully, statementsâ€”of everyone present, the detective on this case could have spent the entirety of those four days doing little more than arranging interviews!
Protecting the Scene: The First Responder
The first person on the scene is immediately confronted with a number of considerations: victims who may be in need of immediate attention, witnesses ready to melt away at the first opportunity, the possibility of further criminal activity, the responsibility of preserving whatever evidence might be remaining and securing a crime scene while maintaining safe corridors for emergency personnel. This person must weigh all these needs and make immediate decisions based on the situation. And every situation is, in some way, unique.
Imagine arriving at a subway platform at 8:30 a.m. to find the victim still on the tracks, an injured passerby sitting on his briefcase, hundreds of people spilling through the scene, and a dozen points of possible egress for the perpetrator. Where, in that milling mess, does the yellow tape belong? Who else should be called in, and in what order should they be called? Is it even possible to secure this scene?
Fortunately, while each scene includes elements that could trip up an investigator, the experience of hundreds of others has provided a rough outline for what must be accomplished, as well as the order in which these tasks should be done. Faced with an overwhelming situation, the first responder can operate on autopilot while impressions sink in and decisions are made.
The Responsibilities of the First Responder
Observe and Establish the Likely Parameters of the Crime Scene
1.As the crime may be ongoing, the first responder must assume the scene is unsecured and dangerous until proven otherwise.
2.Observe the immediate scene, identifying the major physi- cal characteristics, persons (living, deceased, injured, lucid, or confused), and paths into and away from the area. If possible, identify any individual who might have called in a crime and get their names.
3.Note the entrance and exit of any persons or vehicles during the initial scan.
4.Identify the primary scene and any possible secondary sites or paths to and from them.
5.Establish a safe path of access or wait until one can be established safely.
6.Make sensory observations, including sights, sounds, and smells.
Initiate Safety Procedures
7.Based on observations, contact any personnel needed to ensure the safety of additional responders. If there is evidence of a bomb, beware of secondary explosions designed to ensnare responding emergency personnel. If thereâ€™s a possibility of biological or chemical hazards, like a natural gas leak, or the continued presence of dangerous persons, ensure that appropriate warnings are passed to everyone approaching the scene.
8.Ensure that those remaining within the scene, including victims or witnesses, are aware of any possible hazards.
Provide Emergency Care
9.Determine the status of witnesses and victims, checking for signs of life and medical needs.
10.Call for medical backup and provide first aid if required.
11.Guide medical personnel along the path that is both least likely to impair physical evidence at the scene and to quickly deliver them to victims.
12.Ensure medical personnel are aware of the need to preserve evidence (i.e., slugs or victimsâ€™ clothing) and to preserve the crime scene as untouched as possible.
13.Find the names of facilities to which victims may be transported.
14.Get initial statements from victims who can provide them.
15.Ask medical personnel to note statements made by victims.
16.Attempt to have law enforcement personnel meet the victims at the hospital if no one is available to travel with the victims from the crime scene.
Secure the Scene
17.Beginning with those already on the scene, escort all persons to a safe and secure location from where they cannot alter the scene. To prevent discussion of the crime or the scene, it is best if persons are moved separately.
18.Make preliminary separations of witnesses, suspects, bystanders, and begin identification, interviews, or consolation as appropriate.
19.Ensure that â€œofficialâ€? bystanders (reporters, non-involved law enforcement personnel, etc.) do not gain access to the scene.
Physically Secure the Scene and Evidence
20.Working outward from the primary incident site, se- cure the primary incident site, all sites of ingress and egress, and any vehicles that may be associated with the crime, the witnesses, suspects, or victims. Use barrier tape, flags, flagged ropes, or other suitable materials.
21.If it appears likely that the media will become intrusive, arrange for visual barricades.
22.If specific apparent evidence is in danger of destruction, cover it or secure it in some other manner.
23.Document. Take note of everything done to date, persons on the scene, persons called to the scene, investigative animals on scene, locations of vehicles, positions of doors, environmental conditions, etc. Whenever possible, include sketches, measurements, and diagrams.
24.Establish a â€œcontrol centerâ€? location for allowing or denying access to the site and a â€œpoint officerâ€? in charge of passing information into and out of the site, thereby limiting the number of people crossing the line.
25.In collecting evidence, carefully consider search and seizure issues and contact appropriate authorities for assistance.
26.In addition to ensuring the physical security of evidence, itâ€™s important to try to protect the crime scene from atmospheric changes where possible. For instance, itâ€™s helpful to leave AC/heating controls in place, windows open or closed, and electrical devices on or off as found. More obvious disruptions (smoking, eating, coughing, etc.) should also be avoided at the crime scene.
27.If items must be removed, first document their original locations and conditions as thoroughly as possible.
Release the Scene
28.Once appropriate authorities arrive, release the scene, documenting who has released it and to whom. Apprise new authorities of any outstanding or imminent issues.
29.Provide the control center log of personnel arriving and leaving.
30.Remain available until relieved.
31.Continue to flesh out documentation as possible.
32.Ensure that all notes are clear, all diagrams are well labeled, and, when time allows, all notes of the incident are typewritten and copied to all appropriate files and personnel. Note the environmental conditions and follow up any outstanding items.
33.Review incoming information and compare it to contemporaneous notes to find possible discrepancies.
34.Provide a narrative account of all activity occurring up until the point of release.
Now the scene of the crime is also a â€œcrime sceneâ€? ready for criminalists, technicians, and forensic scientistsâ€”the next stage of the investigation.
Special Problems: The Not-So-Obvious Crime Scene
â€œMurphyâ€™s Law is tattooed on the inside of every law enforcement officerâ€™s eyelids.â€? â€”Purcell Windsor, Scotland Yard
Few criminalists (as theyâ€™re known in the United States) or scene-of-crime officers (as theyâ€™re known in the United Kingdom) would disagree with Windsorâ€™s statement. Even under seemingly perfect conditions, with unlimited time to secure a scene, unlimited personnel to work a scene, careful, dedicated law enforcement people willing to let everyone do their job to the best of their ability, and an unlimited budget for forensic work, things go wrong.
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