Practical Homicide Investigation. (Vernon J. Geberth) Quy trình điều tra

8. Scene Search

The search of the crime scene is the most important phase of the investigation conducted at the scene. Decisions of the courts restricting admissibility of testimonial evidence have significantly increased the value of physical evidence in homicide investigations. Therefore, law enforcement personnel involved in the crime scene search must arrange for the proper and effective collection of evidence at the scene.

Physical evidence, which is often referred to as the "unimpeachable witness," cannot be clouded by a faulty memory, prejudice, poor eyesight, or a desire not to get involved. However, before a forensic laboratory can effectively examine physical evidence, it must be recognized as evidence.

Practically speaking, anything and everything should be considered as evidence until proven differently. I cannot recall how many times I found myself along with my detectives returning to a crime scene. This was after we received additional information, which revealed that some seemingly innocuous item was actually an important piece of evidence. That is why it is imperative to hold onto the crime scene as long as possible. Some item that didn't seem significant on the first day of the investigation may suddenly take on the intrinsic value of gold.

An excellent example of the Practical Homicide Investigation principle that anything and everything should be considered as evidence is the case involving serial murderer Danny Rollings, who became known as the "Gainesville Ripper." He had been staying in the woods at a campsite near an apartment where 18-year-old Christa Leigh Hoyt had been murdered. The police, who had been scouring the woods looking for anyone or anything suspicious, came upon Rollings and another male on their way back to a campsite. When the police ordered the two men to halt, Rollings ran away. The police questioned the other male, who remained behind. He led them to the campsite where Danny Rollings and he were heading.

When the officers discovered the campsite, they found a number of items that would later link Rollings to the five murders. However, the only item that seemed important at the time was a bag of cash covered with pink dye. There had been a bank robbery the previous day and the unknown white male who ran from the police matched the description of the bank robber, who turned out to be Danny Rollings.

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The police collected and secured everything at the campsite, which included bedding, a gun, a ski mask, a cassette tape deck, and a screwdriver. Subsequent laboratory tests were conducted on these crucial materials retrieved from the campsite. The authorities were astonished to find that 17 pry marks at three of the murder scenes were matched to the screwdriver retrieved from the Rollings campsite. In addition, pubic hairs found through vacuuming the campsite matched Christa Hoyt through DNA analysis.

Remember: Do it right the first time. You only get one chance.

Legal Considerations

Once an item is recognized as evidence, it must be properly collected and preserved for laboratory examination. However, in order for physical evidence to be admissible, it must have been legally obtained. The courts have severely restricted the right of the police to search certain homicide crime scenes without a warrant. The United States Supreme Court has rendered three major decisions which require police to obtain a search warrant to search a location where the suspect and the deceased share a proprietary right to the premises.

In Mincey v. Arizona (437 US 385, 1978), the Supreme Court said that the police had violated the defendant's Fourth Amendment rights. Mincey, who was a dope dealer, had shot and killed an undercover narcotics officer during a drug raid. Mincey was wounded and one of his companions was killed in the subsequent gun battle. Following procedure, the narcotics officers secured the premises and notified Homicide. Homicide detectives conducted an investigation during which hundreds of pieces of evidence were seized by the police over a 3-day crime scene search. Mincey was convicted of the murder of the undercover officer. The conviction was overturned by the Supreme Court, which maintained that Mincey's Fourth Amendment rights were violated and that the police should have secured a search warrant. The Supreme Court basically informed law enforcement that "there was no homicide crime scene exception" to the Fourth Amendment.

Did we in law enforcement get the message? No.

In 1984, the Supreme Court once again stepped in to address the same issue in Thompson v Louisiana (469 US 17, 1984). In the Thompson case, a woman who was reportedly depressed shot and killer her husband. She then took an overdose of pills in an attempt to commit suicide. She suddenly experienced a "change of heart" and decided she did not want to die. She called her daughter, who in turn called the sheriff's department, which dispatched an ambulance and deputies to the woman's home. The woman was transported to the hospital, where she was treated. Investigators were called to the house and gathered evidence of the murder in the crime scene. The woman was subsequently charged and convicted in the murder of her husband.

The Supreme Court ruled against the State of Louisiana, citing the Mincey decision and the expectation of privacy provided in the Fourth Amendment. The woman's conviction was overturned. Once again, the courts ruled that there was no homicide exception and that the police were required to obtain a search warrant. Did we in law enforcement get the message this time? No.

In 1999, the Supreme Court once again stepped in to address the same issues raised in the Mincey and Thompson cases. This time it was in Flippo v West Virginia (98 US 8770, 1999). Flippo was a pastor who reportedly was having a homosexual affair with a member of his congregation. His wife had discovered the relationship and was going to divorce him. Flippo convinced her that they should reconcile and talked her into going on a camping trip. They went to a cabin in West Virginia that the pastor had rented. While at the cabin, the pastor reported that they had become victims of a home invasion during which his wife was fatally beaten and the pastor was slightly injured.

The police were not impressed with Flippo's injuries. He was brought to a local hospital and "patched up." Investigators processing the crime scene came upon Flippo's briefcase. Inside the briefcase were various pornographic pictures of Flippo and his male lover engaged in sexual activities. These materials, which represented motive, as well as the other evidence seized from the cabin were introduced into trial. Flippo was convicted of the murder of his wife. The conviction was overturned based on the same issues raised in Mincey and Thompson. The message is quite clear:

A search warrant should be secured before any crime scene search is undertaken under these circumstances. There is no "homicide scene exception" to the Fourth Amendment. Any extended search of a homicide scene, without consent or exigent circumstances, requires a search warrant.

Homicides involving common-law relationships, husbands and wives, or family disputes may necessitate that the detective secure a warrant before a premises can be searched. The professional homicide detective must be aware of the legal requirements for a warrant dependent upon Supreme Court decisions, as well as state law and case law within his or her jurisdictional purview. An additional consideration is the dynamics of the event, which may present legitimate search warrant exceptions. The courts have recognized certain circumstances which allow for exceptions to the requirement of a search warrant. These exceptions are emergency or exigent circumstances, evidence in plain view, postarrest search of an individual for weapons and contraband, and consent.

The ruling in the O.J. Simpson hearings that the authorities properly entered the compound of Mr. Simpson based upon exigent circumstances is an example of a search warrant exception. In addition, blood evidence on the subject's Ford Bronco and in the driveway of his residence, which was in plain view of authorities, was also allowed into evidence.

Figure 8.1 SEARCH WARRANT EXCEPTIONS. This graphic used by the author indicates the search warrant exceptions. (From the author's files.)

Practically speaking, if there is any possibility that evidence you are about to seize for use in a homicide prosecution requires a search warrant, get the warrant. You will save a lot of headaches later.

Warrantless Searches Where Suspect Shares Possessory Right to Premises

Almost every crime will constitute an emergency that justifies law enforcement's warrantless entry to the scene. Traditionally, courts have recognized three.

Threats to life or safety

Destruction or removal of evidence Escape

Officers are authorized to do whatever is reasonably necessary to resolve the emergency. Once the emergency is resolved, the emergency exception is negated.

Practical Examples of Reasonableness: Officers Arriving at Scene of Violent Crime

• They can unquestionably sweep the premises in an effort to locate the victim, additional victims, and or the suspect.

• If a body is found, the police can take the M.E. into the scene to view and collect the body

• They may have probable cause to believe a crime scene contains evidence that will be destroyed if not quickly recovered. That evidence may be retrieved as part of the emergency.

• The "plain view" doctrine can be followed.

• They can preserve the crime scene. (This is considered reasonable.) • They can document the scene (photographs, videotape and diagrams).

Physical Evidence

Physical evidence refers to any tangible article, small or large, which tends to prove or disprove a point in question. It may be used to reconstruct the crime, identify participants, and confirm or discredit an alibi.

Homicide and sexual assault crime scenes usually contain an abundance of physical or trace evidence. The systematic search for, collection of, and preservation of physical evidence is the goal of the crime scene search. Therefore, the detective supervisor should organize the crime scene search so as to collect as much physical evidence as possible. In addition, the search must be based on constitutionally legal grounds, and the evidence collected must be properly documented and handled so that it may be presented in court later. It is imperative that each piece of physical evidence be treated separately and carefully to avoid cross contamination.

Types of Physical Evidence

Transient evidence. This type of evidence is temporary in nature. It can include odors, temperature, imprints and indentations in soft or changing materials (butter, wet sand, snow, or mud), and markings (e.g., lividity, blood spatters on moveable objects).

Pattern evidence. Pattern evidence is produced by contact. Blood splatter, glass fracture patterns, fire burn patterns, furniture position patterns, projectile trajectory, tire marks, modus operandi, clothing or article patterns, and powder residue patterns are considered pattern evidence.

Conditional evidence. Caused by an action or event, conditional evidence can be lighting conditions at a crime scene; odor, color, direction of smoke; flame (color, direction, temperature); location of evidence in relation to the body; and the vehicle (locked or unlocked, lights on or off, window open or closed, radio on or off, mileage).

Transfer evidence. Transfer evidence is generally produced by the physical contact of persons or objects, or between persons or objects. It is characterized by the linkage concept.

Trace evidence. A principle in homicide investigation refers to a theoretical exchange between two objects that have been in contact with one another. This theory of transfer or exchange is based on Locard's "exchange principle." Edmond Locard, a Frenchman who founded the University of Lyon's Institute of Criminalistics, believed that whenever two human beings come into contact, something from one is exchanged to the other and vice versa. This exchange might involve hairs, fibers, dirt, dust, blood, and other bodily fluids, as well as skin cells, metallic residue, and other microscopic materials. In Practical Homicide Investigation, Locards' principle is summed up as follows:

1. The perpetrator will take away traces of the victim and the scene.

2. The victim will retain traces of the perpetrator and may leave traces onthe perpetrator.

3. The perpetrator will leave behind traces at the scene.

The Concept of Linkage

Dr. Henry Lee, a forensic scientist who is the director emeritus of the Connecticut State Crime Lab, developed the concept of linkage as the basis for any crime scene examination. Figure 8.2 is a visible representation of this concept.

The goal is to establish a link between the various facets of the crime scene, the victim, physical evidence, and the suspect. All of these components must be connected for the successful resolution of the case. The basis of conducting such a fourway linkage rests on Locard's principle of the "theory of transfer and exchange."

Remember: Anything and everything may eventually become evidence.

An excellent example of the four-way linkage concept was presented by the prosecution during the O.J. Simpson case. The "trail of blood" theory based on the DNA analysis indicated that blood drops at the scene of the double murder of Nicole Brown Simpson and Ron Goldman, as well as blood in O.J. Simpson's Ford Bronco and his residence, positively identified O.J. Simpson as the suspect. The

Figure 8.2 LINKAGE CONCEPT. (Reprinted with permission of Dr. Henry Lee, Ph.D., Crime

Scene Investigation, Taiwan, China: Central Police University Press, 1994, p. 80.)

DNA analysis of three stains on the console of Simpson's vehicle indicated that droplets were a mixture of blood from Mr. Simpson, the blood of his ex-wife Nicole Brown Simpson, and the blood of Ron Goldman. The famous bloody gloves presented as evidence provided the crucial linkage. One glove was found at Bundy Drive, the scene of the double homicide. The matching right-hand glove was found at O.J. Simpson's estate.

DNA testing of the glove found at the estate indicated that blood matching Simpson's and the two murder victims' "linked" him to the murders. DNA testing of the blood on the glove at Bundy Drive matched O.J. Simpson's blood. The ski cap found near Ron Goldman's body had fibers like those from the carpet in Simpson's Ford Bronco. Goldman's shirt contained a head hair that matched O.J. Simpson's. The socks found in Simpson's bedroom bore traces of blood from Simpson and his ex-wife, who was one of the murder victims. Dr. Cotton, from the DNA testing firm Cellmark, stated that the odds that the blood found at the crime scene belonged to anybody except O.J. Simpson were 1 in 170 million.1

Dr. Cotton also stated that no one on the face of the Earth except for Nicole Brown Simpson could have blood matching the stain found on O.J. Simpson's sock in the bedroom of his home.1 A second DNA expert, Gary Simms, informed the court that the odds that the blood on O.J. Simpson's sock came from someone other than his slain ex-wife were a whopping 7.7 billion to one.2*

From my perspective as a homicide and law enforcement consultant, this evidence represented the ultimate forensic evidence case. In fact, I would prefer to have this type of "unimpeachable evidence," which positively links a suspect to the crime, as opposed to relying on eyewitness testimony.

On October 3, 1995, however, the jurors in the O.J. Simpson case totally rejected the State's evidence and voted to acquit Mr. Simpson of the murders of his ex-wife and Ronald Goldman.

This extremely controversial verdict was rendered in less than 4 hours after 9 months of trial testimony. Early in the trial, the defense team introduced the issue of race and played upon the emotions of the predominantly black jury. The sad truth of the matter is that the Mark Fuhrman tapes actually validated the defense position that their client was a victim of a police frame-up. The murder trial was turned into a race trial. Despite the overwhelming physical and forensic evidence linking Simpson to the murders, the jury rejected good solid physical and forensic evidence and rendered a not guilty finding.

The DNA analysis of the evidence in this case overwhelming inculpated Mr. Simpson, so much so that in response to his vow to catch the "real" killers, "a somber District Attorney Gil Garcetti bitterly dismissed Simpson's promise, insisting that the evidence still overwhelmingly proved O.J. was a cold-blooded killer. And he declared the investigations into the murders closed."3 In addition, the Los

* Additional sources: Today, January 23, 1995, p. 3A; New York Daily News, January 25, 1995, pp. 2, 3; New York Daily News, May 12, 1995, p. 3; New York Daily News, May 17, 1995, p. 8; New York Daily News, May 18, 1995, p. 4.

Angeles Police Department announced that it would not reopen the case because its investigation indicated that Simpson had committed the murders. In a USA Today report published in the Rockland Journal News, "Los Angeles Police Chief

Willie Williams said he had no plans to reopen the probe."4

The goal in the linkage concept is to establish a link among the various facets of the crime scene, the victim, physical evidence, and the suspect. Despite the verdict in the Simpson case, the linkage concept clearly established these facets of the event.

I recommend the Practical Crime Scene Processing and Investigation textbook by Ross M. Gardner as an additional resource for the important considerations in crime scene processing. This book, which is in my Practical Aspects of Criminal and Forensic Investigations series, illustrates a number of practical and proven methods and procedures.

Methods of Crime Scene Search

The method selected for search of the crime scene is usually determined by the size, location, and complexity of the scene. Many criminal-investigation textbooks describe various types of crime scene searches. However, there are actually only six basic methods which are universally accepted. These are (1) the strip method; (2) the spiral method; (3) the wheel method; (4) the grid method; (5) the zone method; and (6) the line method. Practically speaking, it does not really matter which method you select, as long as the search is systematic and complete.

Figure 8.3 STRIP METHOD. This method can be used effectively if the area to be covered is large and open. It is relatively quick and simple to implement and may even be performed by a single investigator in a limited area such as a room.

Figure 8.4 SPIRAL METHOD. This method, sometimes called the circle method, is effective in a small area. However, as the circle widens, evidence can be overlooked. The searcher begins at the center or the perimeter and moves in a circular path.

Figure 8.5 WHEEL METHOD. The searchers gather at the center of the scene and move out in spoke-like directions. The obvious drawbacks in this method are the possibility of ruining evidence when gathering at the center and the ever increasing distance between searchers as the investigators move outward.

Figure 8.6 GRID METHOD. This is the best procedure to cover a large area. The searchers move parallel to one another and cover the same area twice. There are a number of variations of this method. The grid method is considered the most thorough system for covering large areas with a number of searchers.

Figure 8.7 ZONE METHOD. The area to be searched is divided into squares or sectors. An officer is assigned to each zone, or set of squares if the zones are further divided. This method is effective for indoor locations.

Figure 8.8 LINE METHOD. Outdoor scenes can be difficult to search due to vegetation and topography. One of the quickest and easiest methods to use is the line search. The officers are lined up next to one another and proceed along a straight line as they search a designated area.

Formulating the Search

The search for evidence begins with the isolation and protection of the scene. The searcher must ascertain that the scene is intact and then proceed to reconstruct the events that have transpired since his arrival.

Photographing and recording the homicide crime scene is a major facet of the investigation. It is extremely important that this be accomplished before anything is touched or moved at the scene. Also, it is important while photographing the scene to eliminate persons or items — including officers and police equipment — that do not belong in the scene. Prior to any search, the scene must be properly photographed and documented. (See "Photographing the Homicide Crime Scene" in Chapter 6.)

Obviously, the best places for obtaining physical evidence are nearest to where the critical act occurred, such as in the immediate vicinity of the homicide victim. However, other areas related to the primary crime scene must not be overlooked, for example:

• The point of forced entry

• The route of escape

• The suspect (clothing, hands, body, hair, etc.)

• The location where the weapon is or may be located

Figure 8.9 LINE SEARCH — OUTDOOR CRIME SCENE. This photo shows an academy class participating in a line search of an outdoor crime scene. The only problem is that the crime scene detectives did not instruct the searchers about cross-contamination or provide the recruits with protective gloves. Only one officer is wearing gloves and those are not crime scene protective gloves. If these officers had recovered any crucial biological evidence, a clever defense attorney could have used this newspaper photograph to criticize the police evidence collection techniques and/or attack the laboratory results. (Courtesy of the New York Post, photographer Jim Alcorn.)

Figure 8.10 DETECTIVE PHOTOGRAPHING THE SCENE. This photo shows a detective photographing evidence in the scene. (Courtesy of Detective Mark Czworniak, Chicago Police Department.)

Figure 8.11 DETECTIVES AT SCENE. This photo shows a detective at the crime scene documenting and taking measurements. (Courtesy of Chief Criminal Deputy Robin Wagg, Douglas County, Washington, Sheriff's Department.)

• A vehicle that was used in the crime

• The suspect's residence

• The location where the assault leading to death took place

• The location from which the body was moved

Before entering the crime scene, the detective supervisor and the homicide investigator must determine its boundaries, decide how to approach it, and determine whether any fragile evidence that requires immediate attention is present. The crime scene should then be photographed and sketched. (See Chapter 6 and Chapter 7.) The scope of the search is usually determined by a theory or hypothesis agreed upon by the investigators, based on their initial observations of the scene. The hypothesis emerges from a set of simple assumptions of how and why the homicide occurred and the sequence of events that followed. This hypothesis is used to guide the investigator in discovering physical evidence. However, remember that anything and everything may be evidence and become significant later. Therefore, every item at the scene must be handled as evidence until determined otherwise.

The investigators must keep in mind that their hypothesis is provisional. If new evidence emerges that suggests a different sequence of events, they must be willing to reassess and modify their hypothesis as the new facts dictate. I have been at many different homicide scenes over the years and have seen initial theories change over and over again. The key to success in this phase of the investigation is flexibility. Practically speaking, use your common sense in this process. Do not get bogged down in theory and hypothetical speculation. Many times the answer you are looking for is right in front of your nose. The problem is that with all the events going on at the scene, it is sometimes easy to miss a simple observation. Your instincts should not be discounted. They can bring you back to reality or direct you to a situation that would otherwise have slipped by.

Crimes of violence such as homicide usually involve some sort of struggle — a break, use of weapons, use of physical force — or other contact between the perpetrator and the deceased. Therefore, there is a good possibility that trace evidence will be found and recovered. Remember the basic theory of transfer and exchange. (See "The Homicide Investigation Starts at the Crime Scene" in Chapter 1.)

In formulating the search plan, you may want to cover some critical areas immediately or may have some question as to what is or is not evidence. Do not be influenced by the original report, the police call, or any initial statements. Note this initial information and then make your determination based on the total information available. Ask yourself the following questions:

1. Is the death caused by

a. Homicide?

b. Suicide?

c. Accident?

d. Natural causes?

2. Do the facts, the crime scene, the statements, and the physical evidence support this explanation?

3. If the death is homicide,

a. What was the means or agency of death?

b. Is the homicide excusable or justifiable?

c. Does it appear that any effort was made purposely to mislead the police?

For example:

i. A simulated burglary ii. Arson

iii. Murder made to look like suicide

iv. Suicide made to look like murder (insurance case?)

d. Is there more than one possible cause of death?

e. Are the witness statements consistent with the facts?

f. Is the time element consistent with the condition of the scene?

i. Are the bloodstains wet or dry? ii. What is the condition of the body (rigor, lividity, etc.)? (See Chapter 9.)

g. Is there a weapon involved?

i. Was more than one weapon used? What does this suggest? ii. Are the wounds consistent with the weapon suspected?

iii. Is the weapon from the premises?

iv. If the weapon was a firearm,

(a) Are any shell casings present?

(b) Are any bullet holes or spent rounds present on the ground, thewalls, the ceiling?

v. Is a weapon under the body?

vi. Was the deceased armed?

During this self-cross-examination, do not make any final evaluation because you are merely formulating a hypothesis to assist you in planning the search. However, you should estimate as closely as possible the time and place of the homicide. In addition, you should have a general idea of how much evidence you plan to collect. During this stage, you will be depending on hard work, common sense, and keeping an open mind.

The Homicide Kit

If the search is to be successful, certain equipment and logistical support must be available to the homicide investigators. Many departments maintain a forensic or crime scene unit that responds to major crimes with sophisticated equipment necessary to conduct an extensive crime scene search.

I recommend that homicide units maintain a portable homicide kit with the equipment necessary for the collection and documentation of evidence from the scene. A practical kit can be assembled at nominal cost and will usually prove to be invaluable to the investigator at the scene. The important consideration in maintaining any crime scene kit is in the inventory and restocking procedure. A maintenance schedule that assures a routine and periodic resupply and replacement of materials must be put into effect. Sirchie® Fingerprint Laboratories supplies excellent crime scene kits and accessories. Although any number of items may be included, a good homicide kit should contain the following.

Crime Scene Integrity Kit

Crime scene barrier tape ("Crime Scene — Do Not Cross" type)

Crime scene cards

Rope and/or line (rope at least 100 ft)

Crime scene screen

Crime scene tent (to prevent media or onlookers overhearing observations)

Evidence Collection Tools

Basic tool kit containing:

Hammer and nails

Screwdrivers (Phillips and straight edge)

Pliers

Vise grips

Saws

Crowbar or pry bar (2 ft)

Crescent wrench

Wire cutters

Knife (multipurpose)

Shovels

Collapsible shovel

Saw (keyhole type)

Thermometer

Tape recorder with microphone

Extra blank tapes

Cassette recorder with extra batteries and AC/DC hook-up

Clipboard

Measuring tape (100 ft, steel)

Razor blades (single edge)

Adhesive tape

Cellophane tape

Pencils and marking pens

Straight-edge ruler

Swivel mirror with 12-in. handle

Light socket extension cord

Surgical gloves

Cotton gloves

Cotton cloth

1 Box of cotton swabs (e.g., Q-tips®)

Sterile disposable pipettes

Forceps and tweezers

Glass cutters

Sterile disposable scalpels

Flashlights (2 cell or 9 V with extra batteries)

Spotlight (12 V, 50-ft extension)

Electric extension cords, 50 and 100 ft)

Drop light

Spare bulbs

Alternate light source (ALS)

Spare barrier-filter goggles for ALS

Magnifying glass

Magnet extension rod

Metal detector

Safety pins

Steel tape (12 ft)

Lumber crayons

Box of chalk

Tongue depressors (50)

Ball of twine

Paper towels

Putty knife

One pair scissors (8 in.)

Sieve screens

Hand shovel and/or trowels

Fingerprint Kit

Fingerprint powders (regular and magnetic) as well as various color powders

Fluorescent powder

Fiberglass brushes for each color

Magnetic brushes

Lifting tape

Hinge lifters

Rubber or gel lifters

Fingerprint cards

Fingerprint-taking pads

Fingerprint ink and cleaners

Postmortem fingerprint tools

Finger-softening kits

Luminol

Phenolphtalein

Leucomalachite green

Leucocrystal violet

Iodine

Ninhydrin

Silver nitrate

Amido black

Fluorochromes (fluorescein)

Tetramethyl benzidine

Specialized light source

Small particle reagent

Cyanoacrylate (glue fuming)

Portable fuming chamber

Photography Kit

35-mm SLR or large-format or digital camera with appropriate lens, including macro

1 to 1 Camera (e.g., Sirchie EV-CAM™ III evidence camera)

1 to 1 Lens adapter for 35-mm SLR cameras

Tripod

Photo placards (numbers and scale type)

High-visibility photo markers

Polaroid® Spectra LE and Macro 5

Off-camera flash unit

Photographic evidence folding scale

Photo evidence rule tape

Surveyor flags

ALS filters

Lens cleaner and paper

Spare batteries (flash and camera)

Video camera

Sketching and Mapping Kit

Magnetic compass

School compass

Straight edge ruler

Tape measures

Graph paper (8 1/2 × 11 in.)

Clipboard

Plain paper (writing tablets)

Pencils and marking pens

Professional drawing instruments

Appropriate crime scene sketch kit templates

Plan template

Layout template

Furnishings template

Lavatory template

Traffic template

Human figure template

Clear plastic triangle template

Casting Kit

Collapsible gallon water container

Flexible mixing bowls

Casting forms

Plaster casting material

Silicone evidence casting kit (e.g., Sirchie)

Dental stone

Spray sealant for loose soil (dust or dirt)

Snow impression wax

Gelatin lifters

Electrostatic lifting device and film

Indelible marking pen

Tape

Evidence Collection Containers

Paper envelopes (small, medium, and large)

Paper bags (lunch and grocery size)

Butcher paper

Paper for creating pharmacist folds

Box of Glassine envelopes

Box of paper envelopes

Plastic bags with zipper closure (various sizes)

Large plastic bags

Evidence collection boxes (various sizes)

Evidence collection tubes

Pill boxes (various sizes)

Evidence boxes (various sizes)

Clean evidence collection jars with screw-on lids

Solid material evidence containers (e.g., sterile paint cans with lids)

Evidence tags

Evidence tape

Indelible marking pens

Lasers and Alternate Light Sources (ALS)

Forensic lasers produce an extremely high-energy beam of light capable of causing fluorescence in certain materials. The fluorescent effect is usually viewed through goggles or lenses. They are quite expensive and require accessory cooling systems. Because of their size, forensic lasers are usually confined to laboratories.

The ALS is more portable and less expensive. It is a high-intensity white-light source with multiple filters that provides several wavelengths of visible light for examining the scene. An ALS source allows the crime scene technician to see and perceive the scene much more accurately. Lasers and ALS units detect body fluid stains, fibers, and various materials that contain chemical substances capable of fluorescence. The ALS can also be useful in locating fingerprints when fluorescent fingerprint powder is applied.

Most of the wavelengths in an ALS are in the visible range of the spectrum. However, an ultraviolet source can be built into an ALS unit. The usefulness of UV depends on the fluorescence capability of the trace evidence. Some obstacles are laundry detergents.

Figure 8.12 ALTERNATE LIGHT SOURCE (ALS). The portable UltraLite ALS is one of the most powerful, serious-level, solid-state forensic alternate light sources. (Courtesy of Mr. Ryan

West, CAO Group, Inc., Sandy, Utah.)