PHYSICAL EVIDENCE COLLECTION
A Training Guide For
Law Enforcement Officers
Wisconsin Department of Justice
Law Enforcement Standards Board
June 2009
Copyright © 2009 by Wisconsin Department of Justice. All rights reserved.
1
June 2009
acknowledgements
Many people contributed to the writing of this manual. The Training and Standards Bureau, Wisconsin Department of Justice gratefully acknowledges the hard work and dedication of the Tactical Skills Advisory Committee, which has worked long and hard to revise the content of earlier manuals and develop new content for the present guide. The current members of the Committee are:
Designated Representatives
Kevin Fults, Sheriff’s Representative
Derek Beiderwieden, Chief’s Representative
Dan Feucht, Wisconsin Technical College System
Duane Meyers, Wisconsin State Patrol
Patrick Mitchell and David Zibolski, Milwaukee Police Department
Cheryl Patane, Milwaukee County Sheriff
Dan Roman, Madison Police Department
Practitioners
Judi Anibas, Eau Claire Police Department
John Flannery, Northeast Wisconsin Technical College
Gary Harvey, Gateway Technical College
William Joers, Price County Sheriff
Michael Koll, Retired Federal Agent
Jeffrey Kostner, DOJ – DCI
Richard Nichols – Lafayette County Sheriff
Jack Pace, Madison Area Technical College
TABLE OF CONTENTS
acknowledgements......
TABLE OF CONTENTS......
INTRODUCTION......
Preliminary Investigation......
R. E. S. P. O .N .D......
FOLLOW-UP......
CRIME SCENE CHECKLIST......
Hazards at the Crime Scene......
CRIME SCENE PROCESSING......
1. Sketch the crime scene......
2. Photograph/videotape the crime scene......
What Can Photographs/Videos Do?......
How to Photograph the Crime Scene......
3. Search for evidence......
Basic Search Patterns......
4. collect evidence......
What is Evidence?......
Proper Handling of Evidence......
Proper Documentation......
Electronic Evidence......
5. Debriefing personnel......
6. Release the Crime Scene......
summary......
LAW ENFORCEMENT RESPONSE TO DEATH INVESTIGATIONS......
Introduction......
CRIME SCENE......
Evidence......
Firearm Injuries......
Edged-Weapon Injuries......
Blunt-Force Injuries......
Asphyxial Death......
Autoerotic Fatalities......
Drowning......
Suicide......
DNA evidence......
changes to the Body after Death......
Decomposition......
Time of Death......
Coroner/Medical Examiner......
Release of the Scene......
summary......
Resources......
index......
1
June 2009
INTRODUCTION
Part of a law enforcement officer’s job is investigating crimes. Crimes most often come to the attention of the police when the police receive a call for assistance from a victim or a witness. The call may come when the crime is about to happen, when it is in progress, or after it has occurred. Police may also observe signs of a crime in progress or of one that has already occurred, and investigate on their own initiative. Crimes may be discovered during the course of another investigation or through tips from informers. Persons arrested for one crime may confess to another about which police may or may not have had previous knowledge. Sometimes police become aware of criminal activity is during an undercover sting or from a confession from someone reporting to the police after learning of a crime through the news. Regardless of how law enforcement learns of the crime, criminal investigations fall into two major types: proactive and reactive.
Proactive investigations involve investigating crimes before they happen, as a preventive strategy. Tactics of proactive policing can include
- Intelligence gathering through surveillance, area surveys of crime patterns, statistical analysis, and infiltration by undercover agents
- Raids or sting operations which arrest a large group of known offenders to obtain information about current criminal activities
Reactive investigations are the more traditional investigative activities that take place after a crime has been committed. These can include
- Interviewing witnesses and victims
- interrogating suspects
- searching crime scenes for evidence
- collecting and examining evidence
- searching other information sources or records for pertinent information
Reactive crime investigation has two major phases: preliminary investigation, often conducted by first-responding officers, and follow-up or continuing investigation, which may be conducted by patrol officers or by detectives or other investigators.
Preliminary Investigation
The preliminary investigation usually begins when you (the uniformed officer) arrive at the scene of a reported and/or witnessed crime, and ends when you file your initial police report. As the preliminary investigating officer, you must obtain, document, and use as much accurate information from the scene as possible. You should approach the scene as though it were your only opportunity to locate, document, and obtain the necessary clues to solve the crime. Keep in mind that each crime scene is unique.
The investigation may be turned over to an investigator/detective after your preliminary work for more complete and detailed follow-up. If so, your investigation will be the basis for the accurate collection of information and evidence during that follow-up investigation. Follow-up will continue as long as evidence is needed for the conviction of any suspects being prosecuted.
Evidence is defined as “anything offered in court to prove the truth or falsity of a fact in issue.” Evidence may be of several kinds and come from several sources:
- Testimonial: spoken evidence of facts personally observed or experienced
- Physical: (real) tangible objects in their original state
- Demonstrative: representations, maps, photos, models, or diagrams used for illustration
- Direct: perceived by one of the five senses
- Circumstantial: based on an inference (single pieces of circumstantial evidence alone are not adequate proof of the elements of a crime, however, taken together an accumulation of circumstantial evidence can be adequate)
The most successful investigations have three major components:
- To identify the suspect(s)
- To locate and apprehend the suspect(s)
- To prove the guilt of the suspect(s) in court.
The identification of the suspect(s) by name and/or description comes from the victim/witness statements at the scene (the “eyewitnesses”), often leading to the arrest of the suspect(s) shortly after the crime occurred. Or the victim/witnesses provide information that is sufficient along with physical evidence from the scene to identify the suspect(s) during the follow-up investigation. Victims and witnesses play a major role in investigations that have little or no physical evidence (for example, child sexual abuse); the interview and the interrogation become major components in solving the crime.
The time period immediately following the commission of a crime is when the witnesses/victim(s) are more likely to be available and their memories of the event will be fresh and uncontaminated. Any police procedure that increases the chances of identifying and subsequently arresting the suspect(s) soon after the crime was committed ensures the success of the preliminary investigation. This will also eliminate the need for any further follow-up investigation.
R. E. S. P. O .N .D
The Incident Response model that you learned earlier in your training (Professional Communications text, pg. 7) covers a general response method to a variety of situations involving law enforcement.
R: Report: The nature and location of emergency is reported. Officer begins to plan his/her response; requests additional resources, and notifies dispatch of arrival on scene.
E: Evaluate: Officer evaluates the situation, makes decision on whether to enter situation or wait for backup (this should include an evaluation for biohazards and the need for protective gear).
S: Stabilize: Officer takes steps to stabilize subjects and the scene.
P: Preserve: Officer takes steps to preserve life and evidence.
O: Organize: Officer continues to evaluate the situation, coordinates additional officers or other resources, and continues to communicate.
N: Normalize: The officer debriefs self and subject, and restores scene back to normal.
D: Document: Officer collects and documents information, evidence, and all action taken.
The investigation of crime is concentrated within the Stabilize (S) through Document (D) sections of the model. The following is a more detailed description of each section as it relates to crime investigation. Each aspect of this model is significant for law enforcement, criminal investigation, and the relationship law enforcement has with the community it serves.
Report
If the crime is reported promptly your quick response may make it more likely the crime will be solved. It is important that you respond promptly to a reported crime not only because of investigative concerns--there may be victims who need medical intervention. A prompt response also helps to maintain the respect of the public, which in turn influences the public’s willingness to trust law enforcement and cooperate with investigators. Finally, a prompt response will help reduce any police civil liability for willful or negligent failure to protect the public from the crimes of other citizens. Your response time may not ultimately affect the success of the investigation—if the crime was reported long after it was committed, for example—but it always reflects on your professionalism.
Evaluate
When you arrive at any emergency, you must quickly assess if there is an imminent threat to any individuals present or to those still responding into the area. Threats can take many forms: weapons, environmental hazards, biohazards, or hostile or unstable individuals. As you arrive at a potential crime scene, you must also take care that your actions are correct. What you do or don’t do at the crime scene can affect outcome of the case. For example, how you conduct the initial interviews, how you process the crime scene, what you identify, collect and preserve as evidence—all these can make a difference in the successful prosecution of the crime.
Upon arrival, make a mental note of all persons in and around the area. Stay objective and focused, but don’t get locked into one interpretation. Stay open to all possibilities, and try to keep the “big picture” in mind. Consider what you are observe in conjunction with whatever information has been broadcast earlier either through dispatch or other officers concerning the event. Keep an ear open for further broadcast information: doing so will continue to keep you informed of other officer’s observations, actions, and positions. Other officers may have observed or detained individuals leaving the area and your awareness may prevent the loss of witnesses, suspects, or evidence from the scene.
As soon as practical, either at the scene or shortly after leaving it, record your observations as field notes, in order to jog your memory when the time comes to document your activity in your officer report. Do not depend on your memory—you will surely forget details when writing your report hours later.
Stabilize
You must make every effort to detain, separate, and identify all persons in the area in order to ensure the scene is stable—the suspect may still be at the scene. Managing people at the scene requires that you use appropriate officer safety and arrest tactics, and may also require additional back-up units. Remember: making the scene safe takes precedence over giving first aid to those inside the crime scene. Be sure to document all that you (and other officers) did to stabilize the scene.
If a victim is seriously injured, but still alive, attempt to take a dying declaration. A dying declaration is a statement made by a person who believes he or she is about to die, concerning the cause or circumstance surrounding his or her impending death. Although hearsay (the dead cannot testify in person) a dying declaration is admissible in court on the theory that a dying person has no reason not to tell the truth.
Once you have provided aid to any victims, locate all other persons in the area. There may be other crime victims or persons who witnessed the event. Each will need contact as soon as possible to ensure their safety and attempt to gain their cooperation to fully investigate the crime.
Preserve
In order to preserve the integrity of the evidence (both testimonial and/or physical), you need to advise all persons to remain at the scene. You may encounter resistance: after the excitement of the event, people often do not want to “get involved.” Nevertheless, you need to identify who each person is: witness, victim, suspect, or simply a bystander who wants to know what the police are doing. Ask each person for some basic information:
- “Did you call the police?"
- "Did you see what happened?"
- "Were you here when it started?"
- "Do you know what happened?"
- "Do you know who was involved?"
Ask each person his or her name and explain that you will need to ask a few more questions. If you have time then or have been assigned to conduct this particular person's interview, then continue with a full interview. If the scene is chaotic or complicated, it is best to have an officer assigned to each person being detained. If this isn't possible, place people apart in separate locations or in separate squads to preserve their memory and avoid contamination. Wait to more fully interview them once things are under control. If you are the only officer handling this particular situation, you should at least separate people and advise them not to discuss the event with each other.
Another reason to detain everyone at the scene is that they may have physical evidence on their persons—evidence they may be unaware of or may be intentionally concealing. You need to keep everyone at the scene until you have determined the extent of their involvement. You may have developed reasonable suspicion that there is evidence to be collected from the person.
Once the scene is stable, you can identify a safe pathway through the scene so that EMS/Fire Rescue can render aid to victims. If possible, determine the suspect's entry and exit points and use a different avenue to reach the victims—rescue workers simply walking in to the scene could destroy valuable evidence.
While detaining people you need to be stay aware of the potential for physical evidence at the scene to be contaminated, destroyed, or removed. Anyone who is at the scene could inadvertently contaminate evidence just by sitting, leaning or walking within an area containing evidence. Do not allow anyone within the crime scene area to smoke, eat, drink, move anything, use the telephone, adjust the thermostat or windows, etc. Keep the scene as close to the way it was when the crime occurred as possible.
Keep in mind the weather conditions and their potential to disturb the physical evidence. Consider protecting the scene with a tent, for example, if there is inclement weather. You must also set up a perimeter around the area to be contained.
In addition to protecting the scene and establishing perimeters, you need to take time to record your observations of the conditions at the scene. Some of the things you should note down include:
- Lighting
- Weather
- Anything that you have observed: possible physical evidence, odors, sounds, vehicles, etc. Any of these might prove to be crucial pieces of information in the successful resolution of the investigation
- Any changes to the scene after your arrival. For example, if EMS attended any victim, note that down, as well as noting any equipment they brought.
- Jot down a field sketch of the area (not to scale, measurements not taken)
In order to preserve the scene of a complex criminal investigation and the physical evidence contained within the scene, you and any other responding officers will need to set inner and outer perimeters. The perimeters should be set with visual markers such as “police” tape, ropes, barricades, or uniformed officers.
The inner perimeter is the immediate area where the crime was committed. It must be large enough to protect any evidence that may exist. To prevent unnecessary loss of evidence, restrict entry to the inner perimeter only to those who have primary responsibility for the investigation. Evidence can be lost by transference. Transference refers to the fact that when two objects touch, tiny pieces of material on one object may be picked up by the other. A simple example is cat hair transferred from furniture to clothing. Trace evidence such as hair, fibers, powder, glass fragments, and so on can attach itself to the shoes or clothing of anyone walking through the crime scene, and be lost from the scene when the person leaves. By the same token, anyone entering the crime scene may introduce traces of material brought in on their shoes or clothing, thereby contaminating the scene.
- Trace evidence can be crucial for a conviction by placing the perpetrator at the scene. Remember, the perpetrator may take away traces of the victim and the scene on his or her body, clothing, or vehicle and leave behind traces of himself or herself at the scene and on the victim.
- Keep a log of who goes in and out of the crime scene, noting the times of entry and exit and the purpose. Identify all authorized personnel and have them document their activities during the investigation. Do not let anyone else enter the marked inner perimeter. As primary officer, your job is to protect the crime scene and to keep track of what responsibilities each officer has been assigned until you are relieved of that duty.
- The outer perimeter is the surrounding area which includes any entry and exit points, or in the case of a shooting, any area where spent ammunition might be found. The outer perimeter should be at least 50% larger than the inner perimeter.[1] This will prevent contamination of the scene, damage to markings, movement of objects, or the possible removal or addition of trace evidence.
For all operations associated with the investigation (such as fire rescue, supervisors, public information officer, other investigators, etc) there is also an extended perimeter, which includes the command post, staging areas, and so on.An additional area outside of the extended perimeter, perhaps at a nearby location, can be set up as a briefing area for personnel, media, family and other interested parties. Always remember that members of the community may be within earshot or view of you and the crime scene. The media or private citizens may take photos and video of you and the crime scene. The media may use extremely sensitive microphones to pick up audio even if they are kept at a distance from the scene itself. What you do and what you say may be seen and heard again by others.