Crime Scene Response Paper
Vincent Strode
The personnel present at a crime scene are typically police first followed by any medical
personnel if required. The first responding officer will be in charge of securing the scene as best
as they can. Their first priority though is calling for medical assistance if there are injured
individuals, and/or arresting a perpetrator if there is one to be found on scene. The first officer is
also responsible for checking the condition of the victim and taking any statements from them or
others involved. When more officers arrive, the scene can be cordoned off and protected. Rope,
barricades, tape, and guards can prevent unauthorized access to the crime scene. A log needs to
be kept of anyone entering or exiting the scene. While at a scene officers should never do
anything that might end up altering a scene such as Smoking, eating, drinking, or littering. The
scene needs to remain as pristine as possible so no toilets should be flushed, faucets should not
be run, temperature should not be touched, fans not turned on and windows not be opened unless
already found that way.
During the lead investigator's initial walkthrough thorough notes should be taken by pen in a
bound notebook detailing the different aspects of the crime scenes original condition. Take note
of things that are present, absent, damage, points of interest, and conditions. These days a digital
voice recorder or video camera could be used to take the initial notes, but at some point they
need to be transcribed back into a printed physical document. Once the searching phase is
complete, notes should be taken about evidence markers left behind. Special notes should be
taken about a victim before a coroner or Medical Examiner removes the body from the scene.
The initial walkthrough begins with determining the perpetrator’s point of entry and exit. From
there an indirect path to the center of the crime scene can be taken. Obvious items of interest are
located and noted, and the conditions are recorded. Notes become very valuable when paired
with photographs. Photos can show the unaltered crime scene long after the scene has been
disturbed. Crime scene photographs are great in the fact that they can show the layout of things
in the scene. They can show objects in relation to each other. There are 4 important sets of
pictures that need to be taken at the scene: an overview, a mid-range, close-up and close-up with
scale. An overview photograph shows the entire area of the scene. It gives a “Big Picture” of
what is being examined. The surrounding areas as well as entrance and exit points from multiple
angles are also documented. The Medium-range photographs show the overview of specific
areas of interest. These pictures are taken with the evidence markers in place, so as to show the
relationship between key pieces of evidence. Close-up photographs show each piece of evidence
in detail. They are taken at a 90゜angle once with a scale and once without. The scale is placed
in such a way that it disturbs nothing. Other angles can be taken after the 90, but it is the most
important and always taken angle. If there is a body at the scene a close-up of the body focusing
on any wounds that are visible and nearby weapons is critical. Once the body has been removed,
it is paramount to also photograph the area underneath the body. Two sketches of the scene are
required a rough sketch to start with and a final one. The rough sketch is done usually on scene
and contains an accurate description of the size of the scene, and shows the locations of
important items to the case. Each object is measured from 2 fixed points in the room. The rough
sketch doesn’t have to be exact looking. The final sketch however needs to be aesthetically
correct. Computer software is now used often for the final sketch to cut down on time and lack of
ability. Video recording a scene can be very useful when used in conjunction with still
photographs and sketches. Using the video camera you would take the same shots as you would
with a still camera. One person films while a second narrates. The down sides to video taping the
scene are that sound can get muddled through side conversations or wind interference. Zooming
or panning can make the video choppy and the camera will inevitably shake due to being held,
making the picture not better than just still photos. A 3-D scanner can be used to create a
panorama of the scene and uploaded into a modelling program to create a 3D model.
There are 5 search patterns used to search crime scenes for physical evidence: The Strip or line
search pattern, the Grid search pattern, the Spiral search pattern, the Wheel or ray search pattern,
and the Quadrant or zone search pattern. The Strip pattern is used when the boundaries are well
defined, and straight lines can be walked. It involves walking from one side of a crime scene to
the other boundary, moving a little bit over and walking back to the first side, thus creating strips
of searched area. The grid search involves 2 investigators walking from boundary to boundary
(like a strip pattern) but doing it from opposite directions at the same time. The spiral search
pattern is utilized by a single investigator and spirals either from the edge of the scene into the
middle or from the center out to the edge. The major issue with this is that a perfect spiral is
difficult to keep up and evidence can be missed. The wheel pattern is used by many investigators
each walking a straight line from the boundary to the center. This leaves all the space between
the search lines unsearched though so it is not widely used. The quadrant pattern sees the scene
divided into zones Each zone can be divided into smaller zones. Each zone has an investigator
searching it. This pattern is best used when the crime scene is over a large area. Finding physical
evidence is one of the most important aspects of the crime scene investigation. Physical evidence
provides the information that informs investigators on what happened and how. For example in a
hypothetical homicide by gunshot, finding the weapon, the bullet, Gun powder residue, Blood
splatter, fingerprints, clothing from the victim, and any fibers from around the area all need to be
collected and analyzed. If it were homicide by Blunt Force Trauma the investigators would be
looking for a very similar list of evidence, but not knowing what killed the victim makes the
search broader. The investigators would be looking for footprints, fingerprints, any blood splatter
patterns, objects out of place that could have been used, fibers from many sources, clothes worn
by the victim, nail scrapings, and any sort of transfer evidence.
Investigators have to collect evidence in such a way that they can prevent any change in the
physical evidence from the scene to the lab. When collecting evidence, forceps are a good tool to
help pick up things so they are not disturbed much. When collecting small hairs or fibers the
forceps are most useful. That evidence can be kept in airtight plastic pill bottles with the pressure
lids for safe transport. Charred debris from an arson scene can be stored in an airtight container
like an unused paint can or tightly sealed jar. Drugs or powders should not be put in an envelope,
but should be placed in a created folded pouch using what is known as a druggist's fold. Fun fact:
We entomologists use a druggist’s fold to keep our insect pins in, before we use them. Special
care must be taken to prevent cross-contamination. Evidence should be bagged separately, Seal
each bag with tape or something to indicate if the item has been opened or not, disposable gloves
and forceps should be used and anything not disposable should be cleaned or sanitized between
collecting different pieces of evidence. Reference samples should be taken from similar areas as
fibers found for comparison. For instance, if soil is collected at an arson scene, a reference
sample of nearby uncontaminated soil should be collected so the two can be compared.That is
known as a substrate control. Buccal swabs should be collected if bloodstained evidence is
collected. A sample from each of the crime-scene participants is necessary. Once the evidence is
collected and packaged, it can be submitted to the lab by mail or by in person delivery. Mail can
be regulated so not everything can be shipped via the mail. An in person delivery should be made
by someone familiar with the case so that if the lab has questions the delivery person can help
answer questions.
Chain of custody is very important for evidence. If it is not respected the evidence and
information gained from it may not be admissible in court. The chain of custody shows everyone
who accessed a piece of evidence, and when they did so. This paper trail is important to maintain
so when asked about in court it can be provided. When the item is collected the item is tagged
and placed into a collection receptacle. That receptacle then also has a label detailing what
evidence is inside, when/where it was collected and by whom. Anytime that evidence is
accessed, the investigator doing so adds their name and date to the form. Care should be taken so
the original seal with all the information is not broken.
Crime scene safety is important not only for the health and safety of the investigator, but for the
preservation of the scene. Gloves should be worn at all times, making sure to change them out
after each piece of evidence. Protective shoe coverings should be worn so as to not contaminate
the scene or bring anything hazardous out with the investigator. Goggles or glasses are a good
idea to wear in case of accidental splashing, but if there is a known splash hazard a face shield
should be worn as well. If biohazards are present, then Masks and protective tyvek suits are the
standard wear. Sharp objects such as knives, razor blades and syringes should be stored in a
puncture proof container. If a Handgun were needing to be collected at a scene, the first step is to
make sure it is unloaded. When handling a weapon it is best to be sure to handle it in places that
are not likely to have latent fingerprints on it. The weapon should be placed in a box with
restraints to secure it, for example Zipties. The weapon should be hand delivered to a lab if at all
possible. At all times the gun should be treated as it is loaded, even if it is unloaded.
Warrants are paramount to the collection of evidence. If evidence is collected and processed
without a warrant, all of it can be called into question and likely thrown out of a case. An
investigator has to work within the public’s 4th Amendment rights to search and seizure. There
are some circumstances where an investigator can enter a scene without a warrant. Those are if
there are emergency circumstances, if there is an immediate threat to loss or destruction of
evidence, searching a person and property on a person in conjunction with a lawful arrest, and if
given consent to search.
The lead investigator is in charge of deciding when all important evidence has been collected and
cataloged. A final survey is taken to be sure all evidence is collected and all investigation
equipment is removed. Any damages to the scene in the process of evidence collection, should
be documented and photographed. The lead investigator can then release the scene to the proper
authorities.
Cited Resources
● Saferstein, R. (2018). ​Criminalistics: An introduction to forensic science​ (12th ed.). New
York: Pearson.
● California Department of Justice, Bureau of Forensic Services. (n.d.). ​FIREARMS
EVIDENCE COLLECTION PROCEDURES​. Retrieved from
https://www.crime-scene-investigator.net/CAfirearms.pdf