Crime Scene Training

Duty Description for the Crime Scene Investigator

CSI Duty Description

by Mike Byrd

Mike Byrd, a Miami Dade County police officer and Crime Scene Investigator passed away peacefully on Friday, February 25, 2008 at 2043 hours after a more than two year battle with multiple myeloma cancer. Mike was 49 years old.  He was the real-life Crime Scene Investigations Officer portrayed today on television shows and the visionary pioneer of forensics techniques that solved crimes.

The Crime Scene Investigations Bureau

The Bureau provides support services in the form of crime scene processing, fingerprint identification, and forensic imaging to department entities and other agencies. The goals and objectives of the Crime Scene Investigations units are the collection, preservation, packaging, transportation, and documentation of physical evidence left at the crime scene.

Introduction to Crime Scene Response

Most police investigations begin at the scene of a crime. The scene is simply defined as the actual site or location in which the incident took place. It is important that the first officer on the crime scene properly protect the evidence. The entire investigation hinges on that first person being able to properly identify, isolate, and secure the scene. The scene should be secured by establishing a restricted perimeter. Using some type of rope or barrier does this. The purpose of securing the scene is to restrict access and prevent evidence destruction.

 Once the scene is secured, the restrictions should include all nonessential personnel. An investigation may involve a primary scene as well as several secondary scenes at other locations. On major scenes a safe space or comfort area should be designated at the crime scene to brief investigators, store needed equipment, or as a break area.

 In critical incident management the protocol that is being taught today identifies a three layer or tier perimeter. The outer perimeter is established as a border larger than the actual scene, to keep onlookers and nonessential personal safe and away from the scene, an inner perimeter allowing for a command post and comfort area just outside of the scene, and the core or scene itself. An extreme advantage will be seen by taking the time to properly teach the uniform officers and first responders to evaluate and secure the scene.

Physical Evidence at a Crime Scene

Evidence used to resolve an issue could be split into 2 areas. Testimonial evidence and physical evidence. The testimonial evidence would be any witnessed accounts of an incident. The physical evidence would refer to any material items that would be present on the crime scene. These items would be presented in an issue or incident to prove or disprove the facts of the issue. What will evidence collected at a scene do for the investigation?

• May prove that a crime has been committed.
• Establish any key elements of a crime.
• Link a suspect with a scene or a victim.
• Establish the identity of a victim or suspect.
• Corroborate verbal witness testimony.
• Exonerate the innocent.

The evidence that is located and recovered at a scene will give the detectives responsible for the investigation leads to work with in the case.

 Types of Evidence

• Impressions include fingerprints, tool marks, footwear, fabric impressions, tire marks and bite marks.
• Forensic Biology includes blood, semen, body fluids, hair, nail scrapings, blood stain patterns,
• Trace Evidence includes gun shot residues, arson accelerant, paint, glass and fibers.
• Firearms include weapons, gunpowder patterns, casings, projectiles, fragments, pellets, wadding and cartridges.
• Question Documents

The Crime Scene Investigator or Evidence Recovery Technician

In the Scientific community the crime scene investigator or evidence recovery technician is accepted as a forensic specialist. His/ Her specialty is considered a professional organized step-by-step approach to the processing of a crime scene. Extensive study, training, and experience in crime scene investigations is needed for the investigator to be proficient in the field. He/she must be well versed in all areas of recognition, documentation and recovery of physical evidence that may be deposited at the scene. A general knowledge of what analysis may be performed in the lab as well as proper procedures in handling, collecting and packaging of items of evidence is needed to assure those recovered items will safely arrive at the lab.

Specialized training

The duties, assignments, and procedures vary from departments and agencies regarding the investigators or technicians. Therefore the job description may vary depending on geographic locations. For example, if you reside in an area with a large population where it consistently ranks in the top 10 nationally in violent crime occurrences, then the evidence documentation and collection portion of a crime scene response can be a full time job. Where as a geographic location with a much smaller population and fewer criminal acts might necessitate a combination of required job skills. There is also the departmental sworn verses non-sworn personnel preference.

 Most departments today prefer, if not require some type of college degree. It would be advisable to contact the departments or agencies where you reside or will be residing to find out their particular requirements and duties.

 Regardless of whether your major education is in general studies, criminal justice or forensics, a suggestion is to augment those studies with minor courses in basic computer training, drafting, and photography. Any curriculum designed for crime scene in criminal justice classes at most colleges will be developed in general studies not in specifics.

 After being selected for employment most departments will have a probationary period where the employee will go through a training period (OJT= on the job training) assigned to a field training officer. Most of the experience to do the job will be gained in this phase of employment. Most departments also offer their employees an opportunity for post employment or in-service training to further the employees development. Most of the post employee educational classes for the crime scene investigator would be specific classes geared to crime scene response, evidence collection, forensic photography, fingerprint technology, homicide and death scene investigation.

 If the student wishes to search, there are a few colleges today that are offering programs for post graduation classes in various forensic disciplines and crime scene response. If someone were interested in seeking a job in evidence recovery, it would help to spend a weekend at an auto body shop gaining the experience of removing a door panel, the seat, carpet, head liner or a light assembly. Many times the investigator will have to remove a door or a section of wall from a structure. Grid, dig, or sift for hours through a burial site.

 Another area to gain experience is visiting the morgue or a local trauma center. This is not a custom tailored job to suit everyone. What man can sometimes do to mankind is not always a pretty sight to see. If you cannot stomach a busy weekend night in the local trauma center or morgue then you will surely not stomach some of the mutilation or uncommon sights that can be common to the job.

Processing the Crime Scene

In an Organized approach to Crime Scene Investigations there are three (3) basic and simple stages in properly processing the crime scene. Those stages consist of Scene Recognition, Scene Documentation and Evidence Collection. An organized approach is a sequence of established and excepted duties and protocols.

An organized approach assures:

• a thorough and legal search is conducted.
• expeditious processing without compromise.
• proper scene documentation.
• proper methods and techniques for evidence recovery.
• proper use and knowledge of resources and equipment.
• all pertinent evidence recovery.
• proper handling and packaging of evidence.
• proper distribution points for evidence analysis.
• proper safety precautions are followed.

Scene Recognition

The recognition or discovery of evidence begins with the initial search of the scene. The search can be defined as the organized and legal examination of the crime scene to locate items of evidence to the crime under investigation. There are several search methods or patterns applied in an organized search. Factors such as the number of searchers, the size of the area to be searched, the terrain, etc. are used to determine the method or pattern to be employed in the crime scene search.

 Since most investigations start with very limited information, care and common sense are necessary to minimize the chances of destroying evidence. A plan of operation is developed and initiated from an initial walk through of the scene. The plan is to decide what evidence may be present, what evidence may be fragile and need to be collected as soon as possible. What resources, equipment, and assistance are necessary for the processing. Consideration of hazards or safety conditions may need to be addressed.

Scene Documentation

In the documentation stage of an organized approach for processing the crime scene all functions have to correspond and be consistent in depicting the crime scene. The final result of a properly documented crime scene is the ability of others to take your finished work and reconstruction the events that occurred at the scene and your courtroom presentation. In the Scene Documentation stage there are three simple steps to properly document the crime scene.

• Written notes and reports.
• Photographs.
• Sketching.

Reports

Each method is important in the proper documenting of a crime scene. The notes and reports should be done in a chronological order and should include no opinions, no analysis, or no conclusion. Just the facts!!! The scene should be documented just as the investigator sees it.

Photographs

The photographs should be taken as soon as possible, to depict the scene as it is observed before anything is handled, moved, or initiated into the scene. The photographs allow a visual permanent record of the crime scene and items of evidence collected from the crime scene. There are three positions or views that the crime scene investigator needs to achieve with the photographs. Those views consist of overall scene photographs showing the most view possible of the scene, mid-range photographs showing the relationships of items and a close up of the item of evidence.

 A close up should be taken of items that have serial numbers, tags and VINs. All stationary evidence where the photograph will be used to assist in the analytical process should be taken using a tripod with the proper lighting techniques for creating any needed shadows. A second photograph adding a measuring devise should be taken of items where the photo will assist in the analytical process.

Sketching a crime scene

Sketches are used along with the reports and photographs to document the scene. A crime scene sketch is simply a drawing that accurately shows the appearance of a crime scene. The sketch is simply drawn to show items, the position and relationship of items. It does not have to be an architectural drawing made to a scale, however it must include exact measurements where needed. The advantage of a sketch is that it can cover a large area and be drawn to leave out clutter that would appear in photographs.

Evidence Collection

The evidence collection or recovery step in crime scene processing includes the methods, techniques, and procedures used in retrieving evidence. Patience and care are very important at the crime scene. The investigator should take the proper time and care in processing the scene. The work is tedious and time consuming.

Teamwork in crime scene investigations is essential. The entire investigation may involve many people from different organizations. Each individual has a vital role in the investigation process. Continual communication among all parties involved is paramount.

 Consideration to comfort has to be given during the process stage. The investigator will continuously be in different positions and moving around. The only limits that the investigator will have during the process of retrieving the evidence will be his/her own imagination. Always make your equipment work for you, don't work for the equipment. The work done at a crime scene is very challenging. Don't just stand and speak of your work. A great investigator-technician allows their work to speak for them!

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Cold Case Squad Protocol

Protocol for Cold Case Squads 

National Sheriff's Association: Serving Survivors of Homicide Victims During Cold Case Investigations:  A Guide for Developing a Law Enforcement Protocol

Advancements in DNA technology and other forensic investigative tools have enabled law enforcement agencies to reopen cases left dormant for years. Although the number of cold cases investigated by agencies on a nationwide basis each year is currently not tracked, the Federal Bureau of Investigation (FBI) does track the number of offenses cleared. In 2009, 66.6 percent of the 13,242 murder and non-negligent manslaughter crimes in the United States were cleared by arrest or exceptional means. While this is a significant clearance rate, it leaves many homicides unsolved each year.

 In response to the advances in forensic technology, many law enforcement agencies have established cold case units with the hope that reexamining evidence will help solve more crimes. As cases are reopened, investigators are contacting survivors of homicide victims. Although survivors may be grateful that their loved one’s murder has renewed attention, the reopening of a case can sometimes have traumatic effects. As discussed in Section 4.1(see link to article below),

 “Training for Investigators,” survivors may experience a resurgence of grief upon learning that their loved one’s case has been reactivated. New activity in their case may give survivors hope that it will be solved. However, if this new activity does not move the case forward, then survivors may re-experience the frustration and grief they experienced when the homicide first occurred.

 A National Institute of Justice (NIJ) report emphasizes that “re-investigating a case may cause renewed psychological trauma to the victim and victim’s family.” Moreover, “it should not be assumed that victims and witnesses, even if they were eager to pursue the case when it occurred, are still interested in pursuing the case.” Finally, the NIJ report recommends that officers re-investigating a case “enlist the aid of victim service providers.” Working in partnership with victim service providers will help investigators better understand and address the needs of survivors.

 In addition to the establishment of cold case units by law enforcement agencies, services for survivors of homicide victims have also been legislated by two states as well as implemented within some federal agencies. In Arizona, “a law enforcement agency that has a cold case shall establish and maintain a cold case register.” In Colorado, there are statutes defining a cold case and creating a cold case homicide team within the Colorado Bureau of Investigation.

  On the federal level, both the Naval Criminal Investigative Service/U.S. Department of the Navy and the FBI have developed protocols to address the needs of survivors in cold case homicides. Click HERE to download this complete report.  

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Gunshot Residue Analysis

What is Gunshot Residue?

Crime scene investigations: Gunshot residue analysis on a single gunpowder particle

Monday, April 7, 2008

Reprinted with permission from LabSpaces.net

With what could be a shot in the arm for crime scene investigators, chemists have developed a 
reliable new test for detecting the presence of gun shot residue. Above is a residue particle -- roughly 1/20 the size of a period -- that has been magnified 200 times with a digital microscope. (Credit: Courtesy of Garrett Burleson.)

NEW ORLEANS — Scientists in Texas are reporting development of an highly dependable, rapid, and inexpensive new method for identifying the presence of gunshot residue (GSR). The test fills a GSR-detection gap that results from wider use of “green” — lead free — ammunition.

It requires only a single speck of GSR smaller than the period at the end of this sentence and could boost the accuracy of one of the most widely used tests employed at crime scenes involving gunplay.

In a poster presented here today at the 235th national meeting of the American Chemical Society, graduate student Garrett Lee Burleson and his advisor, chemist Jorn Chi Chung Yu, Ph.D., of Sam Houston State University in Huntsville, described their new method. It extracts almost all components of gunpowder residue from particles about 15 times smaller than the width of a human hair, without the use of chemical reagents. After extraction, gas chromatography coupled with a nitrogen phosphorus detector is used to separate and identify the analytes.

“Gunshot residue tests are done in almost every case where a shooting has taken place,” Burleson said. “The main focus of our research is to develop a method that will help credibility of gunshot residue evidence in court. You can get results with this test in 30 to 40 minutes with the new test. In addition you only need small amounts of evidence to run the test.”

Many of the current methods are susceptible to outside interferences that can produce false positive or false negative results. For example, most tests require the presence of lead for a valid reading, including two of the three mainstays of residue analysis — the sodium rhodizonate test and scanning electron microscopy with energy dispersive x-ray detection.

But Burleson points out that lead is disappearing from ammunition. That potentially toxic metal poses environmental hazards at outdoor firing ranges, where it can leach into groundwater. In response, manufacturers have begun to create safer, environmentally friendly ammunition out of other metals, such as zinc and aluminum alloys.

This recent trend toward lead-free ammunition, Burleson said, has decreased reliability of gun shot residue analysis and created the need for smarter tests to identify more diverse components of residue in gunpowder, including elements like stabilizers and plasticizers, which are added in the powder during the manufacturing process for safety reasons.

“When a gun fires, the gunpowder explodes, producing gases at enormous pressure that propels the bullet out of the barrel of the firearm,” explained Burleson, a graduate student in the Master of Science in Forensic Science Program at Sam Houston State University. “Some of the residue from that explosion is deposited on the hands of the shooter and the clothing of the victim.” Burleson’s new test, which uses a technology called solid phase micro-extraction combined with gas chromatography, focuses on chemical compounds present in that ejected material. “When you have a residue particle, no matter how small, it’s going to contain signatures of every element in that powder.”

These signatures offer a wider range of detection possibilities compared to traditional methods, he said. Using an alternative method with a scanning electron microscope, for example, a forensic examiner would perform a search for lead, passing up numerous powder constituents in the analysis. “You would just look for the one little piece of metal that might be there, so the analysis could take hours,” Burleson said.

“If you’re looking for powder, however, there’s a lot more of it. You’re getting more of the residue to analyze. It makes it a much more efficient method of detection.” For example, a distinctive combination of certain chemicals, such as diphenylamine, ethyl centralite and nitrodiphenylamine, is typically found only in explosive mixtures and therefore allows for a simple analysis of gunplay at a crime scene.

In contrast, another traditional test for finding gunshot residue, the modified Griess test, often fails because it lacks such specificity. Its analysis is based on the detection of Nitrogen-based compounds called nitrites, which are gunpowder byproducts. But these compounds are also found elsewhere, leading to possible ambiguity in testing.

“Many chemical cleaners — anything that can be used to take off motor oil or freight dust — will test positive for gunshot residue using the Griess test,” Burleson said.

That would make the reading a false positive, which opens the door in court cases for reasonable doubt and possibly incarcerating an innocent person. “The worst thing you can possibly say is, ‘There’s a chance I’m wrong.’ Our preliminary results indicate you can determine the presence of gunshot residue with a high level of confidence.”

More efficient testing also would reduce the need for extraneous tests that require time and money while draining resources from a criminal justice system that cannot afford it, Burleson said.

The research was funded by the College of Criminal Justice and Department of Chemistry at Sam Houston State University.

Burleson’s test could be used as a preliminary or confirmatory one. “As far as a stand-alone test, it’s an excellent, reliable and cheap test to do,” he said. “But for the sake of clarity and thoroughness, examiners will usually run multiple tests, such as the sodium rhodizonate test at the crime scene, and they could then confirm the findings with my method.”

 American Chemical Society (2008, April 9). Crime Scene Investigations: Gunshot Residue Analysis On A Single Gunpowder Particle. ScienceDaily. Retrieved September 7, 2011, from http://www.sciencedaily.com­ /releases/2008/04/080407074558.htm

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Crime Scene Forensics

What Are the Basic Qualifications for a Crime Scene Technician?

The Scientific Investigation of Crime Scenes

Over the past few years many law enforcement agencies find themselves in a severe budget crunch. This has led them to enact changes in their daily operations. One such change is to hire and train civilians to serve as crime scene technicians.

 This method of filling open crime scene technician slots produces immediate savings in that those who land these jobs do not have to be “sworn” police officers. The benefits are fewer and of course salaries are lower too. Some agencies, however, consider this as an “entry level” position and may, based upon the effectiveness of the individual, pick up the cost of sending a crime scene technician to Basic Law Enforcement Training (BLET) when funds are available.

 In many agencies a crime scene technician or a crime scene investigator are virtually the same. In some cases the technician is a pay and training level grade below an investigator, But most agencies merely use either term to describe those individuals tasked with the responsibility of locating, evaluating and collecting physical evidence from crime scenes.

 Here’s an example of an advertisement for crime scene technician from the City of Durham, NC: (Please note that the pay scale is $30,812 – $46,443)

A responsible civilian position with the responsibilities involving detection, collection and preservation of physical evidence found at crime scenes, fingerprint processing and analysis, photography, physical evidence examination and analysis; in cooperation with sworn officers and court officials involved in the investigation and prosecution of criminal cases throughout Durham County; and other forensic duties pertaining to cases under investigation.

To learn more about the requirements, duties, responsibilities, knowledge and abilities, visit the website: City of Durham, NC (durhampolice.com)

 Educational requirements will vary based on the needs of the local area. Most certainly a high school education is a must, but most agencies are seeking a minimum of an Associate Degree in any of the following disciplines: Forensic Science, Criminalistics, Criminal Justice, Chemistry, Biology, or related field from an accredited community or junior college or technical institute.

 Numerous agencies throughout the U.S. also recognize the completion of the home study course offered by the American Institute of Applied Science. Visit the AIAS Website for more information.

 Definitions related to the work of the crime scene technician. These evidence procedures and the order in which they are completed may vary from one agency to another—based upon established protocols. The following procedure is offered as a generalized approach to investigating a crime scene.

 Physical Evidence: Criminal investigation involves people and/or physical objects--things. Crimes are committed by people, but they use certain physical objects to commit these crimes. It is these things used or touched by criminals that constitute what is referred to as physical or forensic evidence.

Crime Scene Security: The specific duty of the first official to arrive at the scene of a crime is to protect and preserve life and property (offer aid and assistance to those present, apply first aid and summon the necessary medical help); and then ensure the security of the crime scene by erecting barriers (crime scene tape) and posting sentry’s at all possible entrances and exits.

 Conduct a Visual Survey of the Scene: The initial walk-through will include a visual survey of the scene, making note of any potential physical evidence. Preliminary photographs and/or video are taken at this time.

 Conduct a Thorough Crime Scene Search: Depending upon the complexity of the scene, more than one technician will be required for the search. Potential physical evidence is located and marked with flags, signs or evidence tents for later close up photos and collection.

 Maintain a Written Log: As the search progresses a written log of all findings is kept.

 Prepare a Crime Scene Sketch: A rough sketch is begun for both indoor and outdoor crime scenes. The sketch will mark the locations of visible evidence and accurate measurements are taken to detail the exact location of each “thing” noted.

 Process the Scene for Latent Fingerprints: Using either latent print powders or chemicals, as the type of evidence requires, any physical object that may have been touched by the perpetrator will be processed.

 Perform Preliminary, Presumptive Tests for Physiological Fluids, Narcotics and Drugs: While confirmatory lab testing will also be required, physiological fluids and drugs should be subjected to presumptive, non-destructive field testing methods.

Collect and Package All Physical Evidence. This is one of the most critical functions of the crime scene technician. Court cases do not take place after a week or so following the investigation. It may take years before a criminal trial occurs. Evidence must be collected, marked and preserved with this thought in mind. For example: DNA and physiological evidence may degrade and become useless over time if steps are not taken to preserve it. Blood and semen samples can lose their value if packaged in plastic containers—especially if they are collected while still in a liquid state.

 As you may plainly see—crime scene investigation is a complex task that must be completed using scientific principles and guidelines. Many criminal cases have been lost in court because forensic evidence was either mishandled, misinterpreted or was completely absent. The crime scene technician is a vital link in the chain-of-evidence, and it is a position that requires sincere devotion to the tasks at hand. The purpose and the integrity of the crime scene technician—as is the evidence he/she collects—are both on trial.

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