Bullet Trajectories at Crime Scenes - Where Was the Shooter Standing?

Recommended Procedures for Documenting Bullet Trajectory

Crime scenes involving the use of firearms present unique challenges for the crime scene investigator, but using relatively simple techniques it is often possible to reconstruct the events that give some indication as to what occurred during the actual discharge of the weapon. By this I mean it is possible to determine the actual path or trajectory of the bullets, and using this information, determine the location of the shooter.

A number of factors must be taken into account including the position of cartridge cases ejected from automatic and semi-automatic weapons. It is therefore essential that the exact position of spent casings be marked and documented before any other investigative procedures are followed.

Document (Photograph & Sketch) Positions of Spent Cartridge Casings

Photography is the first necessity so it is imperative that the crime scene be afforded absolute security. Until spent cartridges are properly recorded-all foot traffic must be banned from the area.

Each spent casing should be marked using standard crime scene evidence identifiers such as "evidence tents," placards, or similar devices.

Typically, overall scene photos are taken first, followed by medium distance and close-ups. Be certain to include other nearby objects in these photos to better establish the true position of each object photographed.

It is also imperative that a crime scene sketch be prepared once photography is completed. Each spent casing should be located on the sketch that includes either triangulation or coordinate methods of measurement.

The physical location of spent casings may tell a unique story of their own. Placement of these objects results from normal ejection by the weapon and may provide limited data as to the location of the shooter, the direction of shots fired and possibly the path taken by the bullet(s). Ejected casings may also substantiate or refute statements from witnesses, victims or suspects.

Methods For Determining Bullet Trajectory

Historically, the technique of "stringing" a crime scene may date back over 70 years. Stringing has been, and continues to be used at crime scenes for the purpose of determining the source of blood spatter and the path of bullets.

Normally speaking, a firearms examiner would be called upon to render expert testimony with regard to the physics and trigonometric calculations regarding bullet travel. But experts with these qualifications are often few in number. It is therefore incumbent upon the crime scene investigator to provide this "expert" with the documentation needed to draw his conclusions.

While other factors may contribute to a determination of bullet trajectory-the most important fact required for there to be even the slightest degree of accuracy is for the bullet(s) to have passed through at least two objects. This will include:

A door and a wall

A two-sided wall

A window and/or a wall, door or victim, etc.

While stringing the crime scene has been the most frequently used method for documenting bullet travel, it does have its short-comings. When a bullet passed through a window, sharp edges are created, therefore if string is used it must be protected (tape or drinking straw). If more than just a few feet of travel is involved, string is susceptible to droop or sagging. It is therefore advisable to use a strong nylon or other synthetic string rather than cotton string.

Alternatives to Using String

An ideal alternative to use are rods of different diameters. With the exception of hollow aluminum rods, most metals like steel, copper or brass may tend to be too heavy. Also consider wooden dowels or plastic and fiberglass rods.

Tools and Equipment Needed for Determining Bullet Trajectory

String (if this is all that is available) Nylon (or equivalent synthetic)

Plastic or fiberglass rods (preferred), multi-colored if possible)

Adhesive tape (duct tape, surgical tape, even fingerprint lifting tape)

Measuring tapes (25-100 ft. w/metric scale)

Photo ID tape or stick-on labels

Evidence collection kit containing sterile swabs and collection containers

Evidence marking labels (adhesive-type)

Protractor (clear plastic) or,

Inclinometer - for measuring angles and slopes

Directional compass (camping-type with aiming sight)

Graph paper for sketching

Marking pens

Carpenter's or brick mason's string (bubble) level. This device is only used if an inclinometer is not available.

Laser pointer

Crime Scene Investigation Guidelines

Due to the variety and complexity of crime scenes, it is impractical to publish specific guidelines. The following guidelines are offered as a starting or reference point. The actual methods and procedures followed will be dependent upon the experience, judgment and training of the crime scene investigator.

Interior Structures and/or Motor Vehicles

The procedures followed when investigating shootings that occurred in a structure or motor vehicle are quite similar. Again, these suggestions are meant to be a starting point and the investigator should-first and foremost-follow departmental guidelines and procedures.

Shot or shots fired through a glass window: By examining the bullet hole, determine if the bullet was fired from outside or inside the window.

Using a sterile swab, collect any possible gunpowder residue from around the bullet hole from the outside. Repeat this procedure, using a fresh swab, on the inside of the window.

Locate any bullet holes inside the structure or vehicle.

Photograph all bullet holes found in the structure and vehicle. Be certain to include a scale and visible marker (stick on label) adjacent to each bullet hole:

1. Overall, wide angle photos

2. Medium distance photos

3. Close-up photos showing scale to determine bullet hole size

Determine if the bullet is lodged in the wall or object it struck. Locate the exit hole, if any.

If string is used, run the string from the bullet hole in the glass to the interior hole. Anchor the string outside of the window by tying it to a pencil, pen, etc., for support. Protect the string with tape or a drinking straw where it passes through the glass. Fasten the other end of the string to the wall or object adjacent to the bullet hole using tape. Photograph the string from a distance, attempting to get the entire run of the string.

If rods are used (preferred method) insert the rod into the entrance hole and through to the exit hole. Photograph the rod in place. Use the inclinometer to determine the angle of the rod to the wall and photograph it.

Prepare sketches as needed with all measurements required to give a full understanding of the reconstruction.

Note: If cartridge cases are found inside the structure, this will indicate that shooting also occurred inside. A thorough search of the room(s) involved is needed to locate additional bullet holes. Repeat the steps above as they apply to the indoor situation.

At no time during this preliminary evidence collection procedure should any attempt be made to recover the spent bullets that may be lodged in walls, ceilings, doors or furniture. Not until all of the above procedures are completed and photos and sketches finished should spent bullets be recovered.

Obviously extreme care must be taken to recover spent bullets. The area where the bullet is lodged (wall, door, furniture, etc.) must be cut out using hand tools. Despite the methods often shown on TV, this is not the time to dig out the bullet using a pocket knife. What is needed is a hand drill to make lead holes and then a keyhole saw to cut around the bullet hole. A sharp knife will be needed to cut into cloth furniture.

Laser Usage

A small laser or laser pointer is also very useful at certain crime scenes for determining bullet trajectory. The laser has, in many instances, replaced the use of string. Some crime scene kits contain a laser that has been modified so that it can be directly attached to the rod protruding from a bullet hole or attaching it to an inclinometer. One drawback of the laser is that the light beam is often invisible in well-lighted interiors.

This factor can be overcome by using "canned laser (aerosol) smoke." The alternative is to darken the room and taking time exposure photos.

Conclusion

Stringing the crime scene during reconstructing is a relatively simple, inexpensive, and accurate method of demonstrating bullet trajectory. It must be emphasized, however, that this determination is not precise, but it is more of a general, or relative, position-fixing method. The use of string is still valid and remains as only one of several methods of determining the point of origin of a gunshot. When feasible for use in court, it remains an excellent demonstrative tool. Learn more about crime scene investigation at the Crime Scene Tech Blog

Please visit the CSI TECH Blog for more free, online crime scene training.

Maritime Crime Scenes - Crime Scenes on the High Seas

Investigating crimes aboard ships at sea

News stories reporting on piracy along the Somalia coast sparked a world-wide cry for conformity in the training of investigative personnel. The most complex factor is, "Just who is in charge?" The complexity may emanate from a scenario such as this: a hijacked ship may be owned by a Dutch shipping company, flagged in Panama, manned by Filipinos and liberated by German Special Forces.

Coordinating law enforcement activities across the globe is a daunting task, and an acceptable outcome depends of good coordination from investigating agencies and the judicial system where the crime occurs. The US Naval Criminal Investigative Service (USNCIS) and Europol recently joined forces to ensure effective prosecution of the criminal element by conducting a joint meeting in The Hague. These combined forces developed guidelines spelling out how to properly investigate maritime criminal acts.

These guidelines propose a uniformly consistent approach by combining standard, accepted crime scene investigative techniques. Additionally, state-of-the-art forensic examination of crime scene evidence is outlined. The NCIS/Europol alliance looks toward biometric and personal identification techniques such as fingerprint and DNA evidence as causing an increase in the potential for maritime piracy convictions across the board.

It is estimated that nearly 15% of the world's oil production as well as 20% of world trade passes through the Gulf of Aden. Food supplies and other essentials like medical and manufacturing parts and supplies are also directly disturbed by acts of piracy. Much of all of this traffic, estimates say 80%, is bound for European countries.

Maritime piracy is a major issue causing considerable concern with the skyrocketing of the shipping costs that include insurance rates and basic operational costs. A major source of income for Somalia has become piracy-related activities worth hundreds of millions of dollars.

All agencies cite the need for professional, in-depth training for crime scene investigators (CSIs). While each country offers varying levels of exposure to the basic essentials, The International Association for Identification (IAI), the world's oldest and largest forensic identification group, offers recognized training and certification programs for CSIs.

The IAI requires training hours that range from a minimum of 48 hours of instruction and a 200-question examination for a Certified Crime Scene Investigator, up to 144 hours of instruction and a 400-question test for a Certified Senior Crime Scene Analyst.

This is all well and good for organized law enforcement, but what happens from the time the crime or act of piracy occurs until a trained CSI reaches the scene or vessel involved? Most often the actual crew of the ship in question can make or break any later criminal proceedings. Experts note that a crime occurring on a freighter would be handled differently than a passenger ship. It is a much simpler matter to "Secure the Crime Scene" until trained investigators arrive on a freighter, but crew members on a cruise ship will be motivated to "clean up the mess" so as not to alarm, annoy or disturb the passengers.

One major cruise line reported that during a two-year period, 102 sexual harassment cases and 113 cases of sexual assault were reported.

CNN reports that, "...though cruise companies don't display crime statistics to the public, they are required to report serious incidents involving Americans to the FBI and U.S. Coast Guard. Salvador Hernandez, deputy assistant director at the FBI in 2007, told lawmakers that the FBI opened 184 cases on crimes that occurred aboard cruise ships between 2002 and early 2007."

The cruise lines, however, consider those numbers quite small when considering that about 64 million passengers were on-board during that same five-year time frame.

The need for some sort of crime scene training for crew members-particularly those working at on-board security-is a necessity

Such training is slow to evolve, and the certification requirements for Ship and Vessel Security Officers (SSO/VSO) that serve on cruise ships is mainly based upon regulatory standards that fail to offer any guidance or standards relating to basic law enforcement activities and crime scene investigation protocol. This lack of technical knowledge and needed experience in performing those tasks needed for properly processing crime scenes often hampers any follow-up investigation, as well as any resulting prosecution and resolution of the charges in criminal court. For more information on crime scene investigation visit: Crime Scene Tech Blog

Expert author Don Penven is a freelance writer and photographer based in Raleigh and Morehead City, NC

Bloodsucking creatures, nationhood, and crime scenes are among topics of exhibitions.

Bloodsucking creatures, nationhood, and crime scenes are among topics of exhibitions. - Philly.com CollectionsBloodsucking creatures, nationhood, and crime scenes are among topics of exhibitions.September 11, 2011Hazel Ying Lee, whose story is part of "Fighting for…

Museumgoers this fall will be able to piece together crime-scene evidence via mass spectrometry, ponder bloodsucking creatures of the imagination, and consider the imperfect mosaic of nationhood as a parade of diverse and unusual exhibitions and programs marches through the region's specialized museums.

Offerings include the start of a yearlong project seeking to "imagine Africa," a show of works exploring the African American imagination, an outdoor exhibition focusing on worldwide malnutrition, and a portable greenhouse of the future, complete with room for future fossils - a kind of museum-to-be.

In addition, the front of the first floor of the newly renovated Philadelphia History Museum at the Atwater Kent will open, with the rest of the museum to follow in the spring. Such varied displays and events promise to keep visitors busy piecing together past, present, and future - not simply looking and moving on.

Stephan Salisbury, Inquirer culture writer

 

Greenhouse and Cabinet of Future Fossils Empress Josephine's greenhouse, featured in the current exhibition at the American Philosophical Society, has inspired a portable, "organic" greenhouse constructed for the society's garden. It will serve as the staging area for a "sound installation," a theater production, and many other activities this fall.

Architect Jenny Sabin cooked up the Greenhouse and Cabinet of Future Fossils; composer Kyle Bartlett created the sound environment, Chaotic Menagerie. And a play called A Paper Garden: An Idiosyncratic and Indefatigable Account of Empress Josephine and André Michaux's Love of Botany is being performed as part of the Live Arts Festival/Philly Fringe.

Greenhouse runs through Dec. 3 in the Jefferson Garden of the American Philosophical Society. A Paper Garden is performed there weekends, the last performances at 1 and 3 p.m. Saturday. (215-440-3400 or www.amphilsoc.org)

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Are You a Crime Scene Cleaner? Know the Different Kinds of "Crime Scenes"

Knowing how to respond to a certain situation is very important for a crime scene cleaner. This is why knowing the different kinds of crime scenes are not just vital but quite critical since a specific kind may need a different approach or system for securing it. Each type of crime scene clean up comes with different levels of hazard and unique grossness to it that may need special actions or methods to deal with. After all, crime scene clean up is not just about apparently cleaning it but assuring that is really clean which will mean a hazard and infection-free place, just like what it have been before the crime happened.

The most common crime scene clean up includes a violent death, decomposing body and methamphetamine labs. For violent death crimes resulting from a crime of homicide, suicides and street accidents, the usual problem encountered during a cleanup is the tons of blood involved. Aside from blood, there are also bodily fluids and blood byproducts that may carry germs, bacteria and infectious diseases. This is the type of crime scene why a cleaner must undergo blood borne pathogen training to deal with it in the safest way possible.

For a scene that involves a decomposing body or a decaying body, it will have a lesser bloody mess but is equally or more gruesome than violent death scenario. However, the gore sight from a violent death will be replaced by a disgustful smell. Decaying body has already gone through changes that results to a release of ammonia gas which is the source of the foul odor associated with it. Although the police or a crime investigator removes the decaying body before a scene clean up, there are still residues from the body such as liquefied body matter and odors and insects that had entered the body carrying the dead's blood. In this case, hard core cleaners like foggers and odor removers are mostly needed.

Lastly, proper crime-scene clean up for methamphetamine labs does not only include cleaning and removing any foul odor from the place. Of the three kinds of crime scenes, methamphetamine labs are the most dangerous and with the highest health risk involved although there is no gross blood factor found in death scenes. This crime scene has a very high level of toxicity and poisons that are infused in every surface in the lab and stays in the air. Exposure to these poisons such as acetone, methanol, iodine and ammonia that usually being absorbed by the skin may lead to serious illnesses and damage to lungs, kidneys and livers. If the place is not yet declared as safe and truly clean, it will also pose great danger to the public. All the things including furniture and furnishings should remove and dispose of properly.

For a professional crime scene clean up service anywhere in the United States, contact http://www.actremediation.com