The Role of the Crime Scene Investigator


H.W. “Rus” Ruslander, MS, SCSA




The chief duty of a Crime Scene Analyst is to endeavor to arrange and collate numerous individual events, details and observations, which present themselves, in an order that may become a part of a comprehensive picture. The crime scene investigator will create a hypothesis based on physical evidence, of the actions of the victims and suspects before, during and after a criminal event. The analyst will also present those findings to a layperson, trier of fact and other investigators in a form consistent with their level of understanding and comprehension since they are the ultimate decider of facts in all cases.


The mental framework that makes crime scene investigation enjoyable involves curiosity, careful observation, discipline in recording events and ferreting out underlying irregularities; regularities in what one sees, hears and discovers. It requires the humility to learn from other investigators coupled with enough skepticism and open mindedness to reject beliefs not supported by fact. It requires a highly detail oriented mindset.


Upon arriving at a scene, the investigator must do many things and process much information. They are usually assaulted by the uniform officers and the detectives, wanting to turn the scene responsibility over to them, and possibly even the “brass” wanting information for press releases. They often find the scene grossly contaminated by supposedly well meaning officers traipsing through it. Sometimes these officers are even observed eating, drinking or using tobacco products within the critical area. Officers have been known to outline the victim or evidence with chalk or even fluorescent orange traffic paint. They have gathered up shell casings and hidden them under paper cups thinking they are being helpful.


The crime scene investigator must be able to bring all this mayhem to a screeching halt and take command of the situation. Bring order to chaos and organize and operate the working of the crime scene as if it were a well rehearsed and choreographed Broadway production. One thing must be remembered above all else, that is, an incident occurred here! A human life may have been taken, or at very least, a crime has been committed! By organizing, controlling, and working the scene using the proper methods, the likelihood of a successful resolution will stand a much better chance of being accomplished.


The crime scene investigator needs to perform, to be the star of the incident. Become the unsung hero if you will. The investigator should begin by meeting with the lead detective and the first officer on the scene. By holding a brief interview session with these 2 people, the investigator will receive information that can assist them in understanding what happened, when it happened and the sequence of the events that occurred. This can be done without the crime scene investigator receiving so much information that his or her perspective will become tainted by what the officer or detective think. It will be sharpened to the point of being able to take the previously received information and meshing it with the information gathered at the scene and coming to a logical and impartial determination of the events.


The job of the crime scene investigator is similar to that of a judge. To gather the facts, weigh the evidence and reach an impartial conclusion based on fact not impulse or improperly based conclusions.


The actual working of the scene begins when the call is received. As you respond, you begin thinking about your impending activities, formulating a mental list of what you will be doing, what equipment you will need and what assistance you will require. Granted, this is in the formative stage. Actual needs will be determined once you arrive at the scene and have the opportunity to determine what actually happened. It is also necessary to ensure that the scene has been secured with an adequate numbers of officers protecting it and you, as well as keeping unauthorized personnel out. That it is large enough to encompass the entire area to be worked. One person should be designated as the record keeper (scribe) who records the name, ID number, date time and agency of everyone who enters and leaves the scene.


Once that has occurred, the crime scene investigator can begin working the scene by photographing it from the outside working around in the entire 360 degrees of the perimeter. Make sure photographs are taken of the entire exterior of the scene from all angles. Take pictures of what is directly across from the scene as well as up and down the street in opposite directions. Try to include such things as natural and artificial lighting, street names and numbers, vehicles and anything else that you feel could be necessary to preserve or record photographically. Aerial photographs should also be taken, if the situation warrants it. It is a good practice to keep a photo log of each picture taken. This log would include the make and model of the camera, lens and flash you are using, the type and speed of the film as well as the number of exposures on the roll. The log would also include the direction the camera is pointing, the f-stop, shutter speed and whether the flash was used or not. Video photography is then taken to supplement the still photography and to give a sense of “being there” to the potential viewers.


After the overall, exterior photos are taken, move in and look for any evidence that will be photographed. This includes such things as footwear or tire impressions, damage to doors, windows or shrubbery. Any property that is located outside that appears to have come from inside should be photographed too. Any signs of serological evidence, ballistic evidence or damage will also be photographed. All of these items must be photographed using overall, midrange and close-up, including close-up with scales, photography. All numbered or lettered markers that are used must be placed so that they are oriented on the same axis. This way, when photographed, all the letters or numbers are in view within a single photograph.


After the exterior photographs are finally completed, a diagram should be completed. This diagram will be a rough, hand drawn product that includes the location of any items of evidence that have been photographed and measurements taken of the scene and evidence. Triangulation, rectangular or baseline measurements are used either singly or in combination. After the photos, diagrams and measurements are completed, the evidence can be collected and preserved for later examination and processing. Be sure to record the following information for each item recovered; date, time, location, measurements, who collected it and


Once the exterior work has been completed, it is now time to begin moving inside. Before this is done however, it is necessary to determine whether a search warrant must be obtained or anyone, or everyone, who has legal standing at the location, can execute written consent forms. Remember, if consent is granted, it can also be withdrawn at any time and the grantor must be present at all times so they can, if they desire, withdraw that consent. What this means very simply is, you cannot transport or otherwise remove  the grantor from the scene for any reason and still continue the search. If you do, you will not be able to use any evidence seized in the prosecution of the case.


The next thing to be considered is what personal protective equipment will be worn. This could include tyvek jumpsuits, rubber gloves, shoe and head covers, respirators and splash protection. SCBA breathing apparatus or hardhats and safety shoes could also be necessary. With regard to gloves, change them often to avoid cross contamination. Remember, just because you have gloves on doesn’t mean you cannot leave your own fingerprints at the scene. Wearing gloves does not prevent the wiping away of fingerprint evidence on items either.


When approaching or maneuvering through any scene, try to avoid walking, driving or going anywhere the suspect(s) or victim(s) may have gone. This will prevent unnecessary destruction or contamination of the scene and any evidence located in it. Walk through the grass not on the sidewalk, walk around the edges of a room not through the middle. Climb or descend stairs along the wall, not in the middle or along the railing. The suspect is as lazy as you are and much less aware of the potential for depositing evidence than you are. Use an access or exit point that was not used by the suspects if at all possible. Establish a safe path for everyone to use. This keeps all traffic confined to one area and manageable. Consider using flags or brightly colored plastic surveyors tape to create a safe path for use by anyone within the scene to use.


Once inside the threshold, begin photographing the interior. Work as you did outside, in a logical manner. Always work in the same direction, either clockwise or counter clockwise. Never change back and forth. This will prevent you from missing something. Repetition is a good thing for the crime scene investigator. Photograph so that a mosaic can be created, do this by paying attention to what you see in the cameras viewfinder and allowing for some overlap as you pan the camera across the room. Remember that any scene is 3 dimensional. Look at and photograph the floors and ceilings too if necessary. Photograph the scene from at least 2 opposite corners. Photographing from all 4 corners is best since it will reduce the chance that something of importance will not be visible. It may not show up from one or two angles but will, in all likelihood, be visible in the third or fourth view.


Once the overall photos have been taken, draw a diagram of this portion of the scene. Include only major items of furniture and the doors and windows, victims and evidence. Do not record pictures hanging on walls or things on the tables unless it has some important involvement in the actual crime. Your photographs will document these other items. Bear in mind, you photograph in toward the “body” of the crime and search outward from it. Once the midrange photos have been taken, take time to locate any evidence, signs of forced entry or signs of a struggle. Now photograph these in the same manner. Upon completion of the still photography, it is time to re-photograph everything using other formats. These formats can include digital still cameras and video photography as well as Polaroid, if your agency still uses that format. Any video photography should be done without sound or narration. A very helpful suggestion, learned the hard way, is prior to actually shooting any scene with a video camera, put a cassette in it and turn it on, film for about 10 to 15 seconds of something that is not related to the crime scene, such as your vehicle. Stop filming, rewind it and play the tape while you watch the screen or viewfinder to make sure the camera was operating properly and recorded the event. If so, you are now ready to use it on the actual scene. Never re-use a tape, especially one that you may have recorded personal things on such as your children at Christmas. In one case I saw, the crime scene investigator used his department VHS-C video camera to record his grandchildren opening their Christmas presents, transferred the images onto a VHS tape and put the used VHS-C tape back in the camera case. The next homicide, there it was, his grandchildren on the first few seconds of a tape of the homicide! You can imagine the embarrassment he experienced in the trail at the hands of the defense attorney. There should not be any people inside the scene while photography and/or taping goes on and they should not be visible in any photograph taken. A useful suggestion while photographing is, use your flash, even in the daylight areas. This use of fill flash will enable you to record information that may be hidden by shadows or the angle of the sun. Consider altering the angle of your flash and bouncing the light off a ceiling in order to reduce shadows behind the subject you are photographing. Sometimes the use of additional, remote flashes, operated by light sensitive “slaves” can help. And don’t forget “painting with light”. By locking the shutter of the camera open and firing the flash numerous times around the area, you would be able to light up the entire scene on one frame of film instead of using numerous individual photos of the same area. This method can easily be accomplished with the use of one assistant. This assistant does not need to be trained; instructions usually take only a minute or so.


Now the attention of the crime scene investigator turns toward identifying items of evidentiary value, documenting their location and obtaining accurate, albeit, “approximate” measurements. Remember, time and distance are ALWAYS approximate. These items are then photographed individually using scales and then collected. If they cannot be collected due to size or location, they should be processed there. By processing, and this could include dusting for latent fingerprints, swabbing for DNA and close examination for trace evidence, the evidence is recovered even if the item must be left at the scene.  Items that are transportable should be carefully and properly packaged for transport to the crime scene laboratory for processing under controlled conditions. Consideration should also be given to using Super Glue fuming to “fix” the latent fingerprint to the surface. This will prevent the accidental destruction of the latent fingerprint in transit.


After completion of the recording and collection of evidence, another walk through of the scene should be done to make sure nothing has been overlooked. Discuss what you have done and what you have found with the detective and other crime scene investigators. We are human and do miss things. By critiquing the scene and your activities before leaving, you reduce your chances of missing important evidence. Remember, once the scene is released, it cannot be revisited in the same condition it was in while you were there. Evidence missed becomes evidence lost forever.

Once satisfied that the scene can be released, make sure all your equipment has been collected and all the evidence accounted for. Proper disposal of trash is mandatory. Decide whether you should put up notices or warnings on the exterior of the building or room if chemicals were used inside. Is there a possibility of liability against you or your agency if someone is contaminated with something you introduced to the scene? Have you properly decontaminated yourself and your equipment? Have you properly disposed of any contaminated items?


Now that you have left the scene, transport you evidence to the laboratory. All film should be turned in for processing to the photo lab. All serological evidence should be air dried and turned over to the lab for processing or refrigerated as soon as possible. Be sure to mark the outside of all packages with biohazard warning labels. Before you process any items for latent fingerprints, decide what methods you will use. Will you use superglue? Will you use fluorescent powders or dyes and an alternate light source? If processing porous items, which method will you use and if using more than one chemical, which order you will use each one. If you have any doubts about the possibility of damaging or destroying the evidence, obtain samples of material that are the same as the evidentiary ones and practice on those samples until you are comfortable that you can perform the necessary processes. Discuss the processing order with the other labs that will also be examining the evidence. Will what you intend to do help or hinder their efforts and vice versa.


After completion of all processing, photograph each item again, photograph any latent fingerprints developed with a scale visible in the photo and the photo taken in a 1:1 ratio. List all items on property receipts, use sequential numbering and continue the numbering sequence onto each consecutive property record. Package them according to the policies and procedures of your department or the agency you will be submitting the evidence to and submit them to the evidence section for storage. Make sure you get signatures of everyone taking custody of the evidence to ensure that the chain of custody remains unbroken and cannot be attacked in court by the defense.


Now it is time to lay out the format of your report. I use a format that begins with an opening paragraph, or more, that details the date and time I received notification of the event, the date and time I began my response and the date and time I arrived on the scene. Why so much interest about date and time? Suppose you respond at 2355 hours on November 23rd and arrive at 0100 hours on November 24th? This needs to be explained. Never assume that the person reading your report “knows what you meant”. You must spell it out for the reader. I never detail where I was or what I was doing when the call came in. This has no bearing on the case. I never indicate in my report anything pertaining to any re-direction orders I may be given. I only address information directly pertaining to this particular case and nothing else.


I then go into a brief description of the scene, weather conditions, lighting conditions and names, including agency, of police officers who are present upon my arrival and the type and construction of the location. After that I usually give a brief synopsis of what I was told by the officers at the scene. From there, I begin listing my actions in an outline format, with a section caption such as “photographs”. I start with a listing of each photograph taken. All this information comes from the photo logs I filled out when I took the pictures. Next, I list all ballistic damage followed by all ballistic evidence if any. Ballistic evidence includes the weapon(s), projectiles, live ammunition, and ammunition components. I follow that by listing all serological evidence, which is basically any body fluid or part including hairs and skin. Finally, a list of any other evidence not covered by any of the previous categories is added. Depending upon the nature and seriousness of the case, I have also included in my narration where and when I recovered each item as well as the measurements taken to locate it precisely. These notations are included in each items’ entry in my report. I will also sometimes refer to each photograph, by number, that the particular item of evidence is shown in. For example, Item #1: A sharp kitchen knife, white metal blade with a black plastic handle. Overall length is 14 inches, handle is 6 inches, and the blade is 8 inches. The inscription “Stainless Steel” is etched on the left side of the blade at the junction of the blade and handle. This Item was recovered on the living room floor of the scene, 13 feet 3 inches west of the east wall and 6 feet 2 inches south of the north wall. Refer to photographs 20, 21, 30 and 45. I determine left and right sides of an object by how it is held in ones hand. Hold an object in your hand. One side will be on your left and the other on your right!


All evidence numbering is done in a sequential manner and is the same as the items’ number on the property receipt. This removes any duplication of numbers and confusion when citing the item, its pedigree and location where it was recovered. This way there will always be only one item bearing that number in any of your reports or testimony. Your number can still identify the item and any other number assigned to it by the laboratory. Laboratories will usually assign their own unique number to each item regardless of your numbering system. For example, they may number items Q-1 or K-1 and your item number may be 27 or 56.  One advantage to this sequential numbering system is that it can continue almost indefinitely. Instead of using double letters or a number with a letter combination, simply continuing in the numerical sequence is done.


After this is accomplished, any final conclusions or determinations can be included as well as the disposition of the evidence for processing or follow-up evaluation by other units or agencies. Hypotheses and opinions should not be included in your report unless you are a recognized expert in that particular area and can substantiate your status through training, certifications or Court recognition on prior occasions.


Supplement reports should also be done for any future activities involving this case, including court or deposition appearances and correspondence to or from outside or internal laboratories and the results of any tests or examinations you requested or performed.


This consistent and thorough approach to all of your scenes and scene documentation will result in a consistently high degree of accuracy and quality. Your work and reputation will be more readily accepted and make the prosecution of your cases that much easier because of the care you took in the case from the very beginning. Remember, it is your name and reputation, respect it and protect it.






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