Forensic Science Essay, Research Paper
The word Forensic comes from the Latin forensus, meaning of the forum.1 In
ancient Rome, the forum was where lawmaking debates were held, but it was also
where trials were held just like modern day courthouses. From that, forensic
science has come to mean the application of the natural and physical science to
the motion of matters within a legal context2. Forensic Science can be viewed as
a tripartite structure consisting of a Collection, which pertains to the science
investigation, Examination, which pertains to the medical investigation and,
Presentation, which pertains to the courts. A forensic case will involve all
aspects of each of the three structured elements, each being as important as the
other. It is obvious that there needs to be a shared approach for the successful
end of each case. Each step in forensic science must be done in an exact order;
therefore it can be assured that the investigation can have few doubts about
what is being debated. In this paper I will focus my attention on the first
aspect of the three-step structure, Collections and Scientific Investigation. I
will show what should be done at crimes scenes, how crime scenes should be
handled and what steps must be followed to ensure that all evidence is
uncontaminated as when the crime was committed.
The purpose of crime scene investigation is to help establish what happened at
the crime and to identify the responsible person or people. Carefully
documenting the situation at a crime scene and recognizing all-important
physical evidence do this. The ability to recognize and properly collect
physical evidence is often times vital to both solving and prosecuting violent
crimes. It is no exaggeration to say that in the majority of cases, the law
enforcement officer who protects and searches a crime scene plays a significant
role in determining whether physical evidence will be used in solving or
prosecuting violent crimes.
Documenting a crime scene and its conditions can include directly recording
brief details such as lighting, furniture, fingerprints, and other valuable
information. Certain evidence if not collected right away can easily be lost,
destroyed or ruined. The range of investigations can also expand to the fact of
dispute in such cases as suicide or self-defense. It is also important to be
able to recognize what should be present at a crime scene, what to look for at a
crime scene and what might appear out of place. A crime scene often does not
relate to the direct area in which a victim or actual crime has occurred, but
the possibility of escape or access routes should also be checked. Anything,
which can be used to connect a victim to a suspect or a suspect to a victim or a
crime scene, is important physical evidence. Richard Saferstein explains,
Physical evidence encompasses any and all objects that can establish that a
crime has been committed or can provide a link between a crime scene and its
victim or a crime and its perpetrator (31). I will now explain the appropriate
techniques and ways a crime scene and physical evidence should be handled and
examined.
One of the first things an officer should do once he gets to the crime scene is
to take control and secure the scene as quickly as possible. This is to prevent
anyone from ruining evidence and to keep unauthorized person or persons out of
the area such as the media, the public or anyone who doesn’t belong. While this
is being done, an officer should also be alert for useless evidence and note if
there are any possible approach or escape routes. After an officer does this, he
should conclude the degree in which the scene has been protected and make sure
there is enough security in the area. All persons entering and exiting the crime
scene should be logged and kept down to a bare minimum to make sure the purity
of the crime scene when the case goes to court. Each person involved in the
crime scene should have knowledge relative to its original conditions to avoid
from accidental movement of objects, evidence or anything, which might hurt in
the investigation of the crime. When all of this is done, the next step that can
occur is the actual inspection of the crime scene.
The inspection of the crime scene will usually begin with a walk through of the
area along the trial of the crime. The trail is that area, which all noticeable
actions connected with a crime, took place. It is also sometimes marked by the
presence of physical evidence; this may include the point of entry, the location
of the crime, areas where a suspect may have cleaned up and the point of exit.
The purpose of the walk through is to note the location of potential evidence
and to mentally outline how the scene will be physically examined. The first
place investigators should look is the ground they walk on. This is to prevent
any evidence from being destroyed and if observed should be marked and warned to
others not to step in that area. As the walk through occurs, the investigators
should make sure their hands are busy and they don’t touch anything. The best
way to prevent from touching anything is to keep your hands in your pockets.
Once the walk through has been completed, the scene should be documented with
videotape, photographs and sketches. Any or all objects can provide a link
between a crime and its victim/suspect; therefore it is very important that the
crime scene be well photographed and recorded
One of the first steps in documenting and recording a crime is videotape.
Videotapes can provide a perspective on the crime scene layout that cannot be as
easily perceived in photographs and sketches. The condition of the scene should
remain unmoved with the exception of markers placed by investigators to show
small things that might not be seen such as bullets, bloodstains or other key
pieces of evidence. A key in videotaping is slow movement through out the scene
and should be done so from beginning to end. It is also wise to go over an area
twice in order to prevent unnecessary rewinding of the tape when viewing and to
make sure the taper has captured everything. Taping should begin with the
general outline of the scene and surrounding area. Taping should continue
throughout the scene using different angles, close-ups, and still shots for a
few seconds. Once videotaping has finished it is then best to also capture the
crime scene with still photography.
Regardless if a scene has been videotaped, still photographs are a must at every
crime scene. Although videotaping does record everything, photographs can
demonstrate certain things such as direct comparison. Actual size photographs
can be used to compare fingerprint and shoe prints photographed at the scene
against the suspect. Again, when photographing, the outer part of the scene
should be taking first to show the surrounding areas, then towards the crime
scene itself. Wide angle photos should be used of the crime scene and
surrounding areas. A good technique to use when shooting rooms is to shoot from
many possible angles such as from all four corners, from a doorway or from a
window. When close-ups are necessary of key pieces of evidence, a ruler should
be photographed with the items where relative size is important. While each
photograph is being taken, a person should also be taking notes on what the
person is shooting, in order at a later date to understand what was trying to be
accomplished. After still photography has been taken, the final step in
recording a crime scene is to sketch and draw the scene out by hand.
While photographs are two-dimensional and often can alter distance and size,
sketches provide the means of showing distance or objects, and an over-head view
of the area and surroundings. A sketch is usually made of the scene as if one is
looking straight down or straight ahead. Measurements should be taken at crime
scene of distances between two objects, room measurements and key pieces of
evidence. Two measurements should be taken at right angles to each other from
two location points. Each measurement should be double measured to make sure
they are correct and accurate. A professional using all the measurements and
notes taken by the investigators can make a final sketch. However, the original
sketches should not be thrown out but saved along with other key evidence in
case a disagreement occurs or something was missed. Once the crime scene has
been recorded with videotaping, still photography and sketches, gathering of
evidence can occur.
Gathering and locating physical evidence is a very slow
done correctly, however, it can surrender many clues. One of the first things an
investigator must determine is the size and area that must be searched. The main
focus search must include all likely points of entry and exits used by the
criminals. When searching, certain patterns may be used to cover and examine the
area. There are about three different ways in which an area can be examined. One
way is a spiral search method, which is by starting in the center of the scene
and work in a spiral outward do this method until all of the scene has been
covered and checked. Another method and usually the preferred method is the grid
method. This is done by marking the crime scene into a grid and walking in a
straight line from one side of the grid towards the other where as you make 180
degrees turn and come back a few steps over from where you just searched. This
pattern overlaps itself and I feel is one of the best search methods. The final
method used is a quadrant or zone search. This is when the scene is divided into
certain quadrants, usually four and each zone is searched with either the spiral
or strip line search. Then after each zone is searched, the overall scene can be
searched using the above patterns.
When evidence is found it must be package and protected in a way that prevents
any physical change from happening from the time it is taken to the it reaches
the crime laboratory. Such things like breakage, contamination, evaporation and
ruined samples can all be avoided with proper handling and packaging. Original
conditions must be maintained at all cost and when ever possible the entire
object should be submitted to the crime laboratory. Good judgment must be
maintained and common sense usually plays a role. Each different item must be
placed in separate containers to prevent cross- contamination. It is also wise
to take comparative samples, so that evidence can be compared to normal or
controlled pieces. Unbreakable bottles with lids are good for such things as
hair, glass, fibers and other evidence. However, when anything contains blood
evidence, it must be placed in a non-seal able container, such as paper bags.
This is to stop bacteria from forming and possibly making the evidence unusable.
Also good for evidence collection are manila envelopes, cardboard boxes and
paper bags. Besides blood, special interest must be made towards clothing. All
clothing must be air-dried and placed individually in separate paper bags to
ensure constant circulation to prevent mold or mildew from happening. The only
time a seal able container must be used, is in the cases when suspicious fires
are being investigated.
Finally, with gathering evidence at crime scenes, an investigator must make sure
he not only labels the evidence, but also makes a correct description on all
sketches and diagrams. Evidence should not be handled a great deal after
recovery and should be kept down to as few people as possible. Investigators
must continuously check paperwork, packaging notations, and other recording of
information for possible conflict or errors, which may cause confusion or
problems at a later time in court.
Once evidence is gathered it must be sent to a laboratory for processing and
further investigation. When items are to be delivered the method usually depends
on how far away the laboratory is from the crime scene. In most cases, a state
or local laboratory is within a few hours and delivery can be made by personal
delivery. However, in some cases when items must be shipped to F.B.I.
headquarters in Washington D.C., personal delivery is usually out of the
question. When an item needs to be shipped via mail, it should be packaged in a
way not to damage it. Postal regulations do forbid such things as ammunition or
explosives from being send through the mail. Each item when shipped should be
logged and sent with a checklist in order to make sure everything shipped is
accounted for. An in depth report should also be sent of the crime, notes, and
why the items were sent and what should be looked for.
Along with the evidence, control specimens should also be sent to the laboratory
so that they can evaluate evidence to a normal piece of what is being looked
for.
One of the main concerns with physical evidence always argued by the courts is
whether or not the evidence was obtained legally. Often with a few major court
cases, evidence has been thrown because it was obtained illegally to make sure
of a conviction. The Fourth Amendment of the U.S. Constitution states, The right
of the people to be secure in their persons, houses, papers, and effects,
against unreasonable searches and seizures, shall not be violated, and no
warrants shall issue, but upon probable cause, supported by oath or affirmation,
and particularly describing the place to be searched, and the persons or things
to be seized.(U.S. Constitution) With this, the Constitution means the police do
have a right to seize items or evidence that might help them in determining a
suspect, however they do not have to the right to take the items illegality. The
police must have probable cause in order to take property and seize items, which
belong to someone else. Unreasonable searches and seizures occur when the
officers in charge do not have the authority to be at a certain place or do not
have the courts or owners permission to look around, or about the person’s
property or area.
One case that clearly shows how illegal searches and seizures took place against
a defendant is in the case of Michigan v. Tyler4. In this case, Loren Tyler who
leased a business was charged with arson after his business was destroyed by
fire. During the investigation, various items and physical evidence were
recovered from the building. However, on three other separate occasions, 4 days,
7 days, and 25 days after the fire, investigators came back to the scene and
again took various items that they thought would help them build a case against
Tyler. Each of these searches was made without a warrant or without consent of
the owner. During the trial, the physical evidence seized in all four searches
was used to convict Tyler of arson. On appeal, the U.S. Supreme court upheld a
reversal of the conviction saying that the evidence was illegal. The other
searches were made without consent, or with out probable cause, the ensuing
reentries to the scene were prohibited and a new trial was arranged on these
conditions. The message as explained from the Supreme Court is clear, When time
and circumstances permit, obtain a search warrant before investigating and
retrieving physical evidence at the crime scene(Saferstein 50).
In conclusion, as we can see through out this report, collection and recording
of a crime scene is very important, with out proper rules and special handling,
a criminal can go free. The purpose of crime scene investigations is to help
establish what happened, and to identify the responsible persons or victims. To
figure this out, careful recording and investigations of a crime scene must take
place. Recording the crime scene details such things as place, time, conditions,
lighting, fingerprints, evidence, etc. To record a crime scene such things as
videotape, still photography and sketches are used to give a story or time line
of what happened and what took place. Once the crime scene has been recorded,
actual inspection for physical evidence occurs. This is where the investigators
look for clues such as fingerprints, bloodstains, items or anything, which might
lead them towards a suspect. When gathering evidence, each item should be place
in separate containers and certain rules for blood stained clothes and fire
investigations apply. The investigators must keep tract and record everything in
which they recover from a crime scene. Searching a crime scene is a long and
thorough process, however, it will surrender many clues when done properly. Once
the evidence is found, recorded and packaged, it must be sent to a crime lab for
further processing. Each item when shipped should be recorded, logged and
accounted for from person to person so when used in a trial, the evidence has
been accounted for from beginning to end. The final thing investigators must
make sure is that all evidence was seized properly and with probable cause. This
is the main reason why in so many court cases evidence is thrown out, improper
searches and seizures. If any investigator is in doubt on whether or not a place
or person can be search, it is always best to obtain a warrant for that such
reason.