Handguns: Range of Fire and Gunpowder Stippling
Written by John Louis Larsen & Arthur H. Borchers   

Investigators confront a multi-faceted problem when they attempt to determine the range of fire in a shooting incident. The following article deals with the gunpowder stippling patterns that are left behind after a handgun is fired, and how they may or may not relate to the distance between muzzle and target.


Image 1

A variety of handguns and ammunition were utilized in this study. The handguns used were: a Colt Trooper Mark III; Rock River 1911A1; Colt Officer Model 6” Target; Sig Sauer Models P220 & P226; Smith & Wesson (S&W) models 6946 and Airweight; Glock models 26, 27, and 30; and a Walther PPK/S.

Each handgun was fired at six different distances: 0 in. (i.e. contact), 6 in., 12 in., 18 in., 24 in., and 36 in. Target material was 0.25-in. thick, white artist board cut into 1-ft. squares. A mounting frame was used to keep each target in a fixed, upright position.

At the introduction of each weapon, several rounds were fired, and the bullets’ average muzzle velocity in feet per second (fps) was measured using a chronograph. Within each batch of cartridges, a round was disassembled and stored. The point of aim was the center of the target board. A 4-ft. carpenter’s measure and plane were affixed and marked with each different distance. The muzzle of the weapon was placed on line with the associated mark and then fired. Six exemplars were shot for each handgun.

This study was prompted by an appeal case pertaining to State of Wisconsin v. Michael H. Fink, 04CF124 (1st degree attempted murder), in July of 2010. On March 25, 2004 in Marshfield, Wisconsin, Michael Fink accidentally shot his live-in girlfriend in the face. The bullet grazed her left cheek, causing a superficial laceration. The officers working the case questioned Fink’s statement concerning the distance from his girlfriend when the S&W Model 626 Snub Nose .357-magnum caliber revolver discharged.

Investigating officers made the determination that the artifacts observed on the victim’s face (see Image 1 above) were powder stippling and not blood spatter. An experiment conducted by the investigators led them to the conclusion that the defendant was located within inches of his girlfriend’s face, thus discounting the defendant’s claim that he was exiting the bedroom (approximately 4 feet from the victim who was sitting on the living room couch).

James M. Mason, Circuit Judge, Branch 2, of Wood County, Wisconsin, ruled that the lead investigator was not qualified to make statements on intent, or to provide an opinion of the facts as to whether the shooting was accidental or intentional, based on the investigator’s experiment.


Image 2

When a shooting occurs at close range (up to 36 inches), gunshot residues may be deposited on the surface of the victim’s skin. Some of the debris associated with this stippling phenomenon are: pitting (or indentation marks) in the skin; burns on the surface of the skin caused by the burning powder; soot on the skin as a result of burned powder, as well as tears and peeling of the epidermis and dermis. In those instances where there is a wound displaying the classic star pattern as seen in Image 2 on the following page. (The surface area was torn or peeled back in all contact exemplars in this study.) A conclusion can be made as to the distance between muzzle and victim—which, in these instances, should be determined to be contact wounds.

In the experiment, tearing and radial creasing extending and surrounding the BHE occurred in exemplars A-M at a 6-in. distance. Radial creasing and torn surface material from the BHE also occurred at a distance of 12 in. on exemplars A, B, D, F-K, and M. Among these exemplars, only one radial crease was observed traveling in a vertical or horizontal direction through the BHE. Exemplar C (Colt Officer Model Target) and exemplar E (Sig Sauer P226) were the only two exemplars at a distance of 12 in. without some form of radial creasing.

In Dr. Vincent J.M. Di Maio’s book, Gunshot Wounds: Practical Aspects of Firearms, Ballistics, and Forensic Techniques, page 111 (1993), he states, “For virtually all handgun cartridges, soot is absent beyond 30 cm (12 in.).” In the study, bullet sooting was observed outside of the contact ring up to a distance of 12 in. The writers observed this occurrence, but also noted that on one of the 18-in. exemplars there were some soot deposits. There was a drastic diminishing of soot deposits beyond the 12-in. exemplars. Soot deposits were viewed as light-gray spots, and were counted along with the powder stippling.

The problem that confronts investigators is that any shot further than a 12-in. distance can easily be misinterpreted. When conducting the experiment, it was found that the size of the powder-load (or grain-count) patterns appeared to be very similar except for the actual stippling count (e.g., Federal .38 Special 125 grain jacketed hollow point JHP+P, versus Federal .45 Caliber, 230 grain JHP). The stippling patterns associated with the range of fire at a distance beyond 12 in. on the exemplars made it extremely difficult to make any sort of determination other than stating that the range of fire was somewhere within 36 in. of the target surface.

Another problem confronting investigators and medical examiners is the position of the target surface. That position should be determined before attempting to make range of fire estimates, except for contact wounds. The victim in Image 1 was sitting on a couch with her head turned to the left while looking at her boyfriend standing in the bedroom doorway (approximately 4 to 6 ft. from her). A graze wound is visible on her left cheek. The problem in this case is in trying to interpret what happened, since the apparent pattern extends evenly across her face. The red tattooing, in the writers’ opinion, was caused by the terrycloth toweling used while trying to stop the bleeding and providing pressure to her face. The investigators used the photograph in Image 1 to make their stippling count.

An investigator must use caution when attempting to interpret the powder stippling or the gunshot powder residue in order to determine the range of fire. Intermediate items such as clothing and fabrics can capture powder and contaminants when a projectile is fired through them. The investigator should thoroughly inspect the shooting incident site for these possible barriers and collect the actual items involved.

Counting protocol for powder stippling in this experiment

An 8-in. square acetate grid was placed over the exemplar with the center positioned approximately over the middle of the BHE. The stippling marks, indentations, burned and unburned powder particles that were embedded on the surface of the exemplar were then counted (see Diagram 1).

Included in this article are two sample series of photographs of gunshot stippling exemplars: Series D (D1-D6) shows range of fire targets for the Sig Sauer Model 220; and Series L (L1-L3) shows range of fire targets for the Walther PPK/S.

Observed on almost all the contact shots were the star-shaped, 5- and 6-point patterns. The approximate diameter of these contact patterns was 1 to 2 in. square.

A word of warning to investigators: Do not attempt to determine caliber of the bullet based on the diameter of the BHE. There are too many variables that can affect the size, shape, and appearance of the BHE. If the bullet tumbles or breaks apart, it can cause a malformation of the BHE.

Conclusion

Some general observations evolved from this experiment. The first was that the powder stippling pattern is related to barrel length, powder capacity of the cartridge, and muzzle distance to the target. A short barrel produced a wider dispersal of unburned and burned gunpowder surrounding the bullet hole entry as observed with the Walther PPK as seen in Series L. Barrels 3.5 in. and longer generated a stippling pattern that was tighter overall. This observation was somewhat expected since more powder is consumed in the barrel before the bullet exits the muzzle.

The contact shots yielded a large blown-out area far exceeding the size of the caliber of the bullet. This is due to the discharge of expanding gas and burning powder exiting and dispersing as the bullet clears the muzzle.

Cartridge capacity will affect the gunpowder stippling: the greater the powder load, the more chance there is of powder stippling. Intermediate targets can eliminate gunpowder residue and stippling and lead the investigator to an inaccurate conclusion. For example, in the case of an individual shot behind a door, the muzzle may be only inches away from the face of the victim but the door interferes and takes on the characteristics of a range of fire of 6 in. to contact.

The writers opine that attempting to make a distance declaration based on observed powder stippling is fraught with subjectivity and can be misleading. The only reasonable conclusions one can draw from the powder stippling is that when the stippling appears locally concentrated, the weapon may have been discharged within 24 in. of the target surface. Gunpowder residue is usually associated with a distance of contact up to 12 in. The determination of distance by counting burned and unburned powder indentations is arbitrary at best.

Terms Used in this Article:

Powder Stippling: Small hemorrhagic marks on the skin produced by the impact of gunpowder particles, or—in inanimate objects—small pits or defects in th eobject caused by the impact of unburned or partially burned powder particles.

Powder Tattooing: The embedding of partially consumed and unconsumed powder particles in the skin with accompanying hemorrhagic marks associated with living skin.

Bullet Wipe: The discolored area on the immediate periphery of a bullet hole, caused by the transference of residues from the bearing surface of the bullet. These dark-gray to black residues typically contain carbon, lead, bullet metal, and possibly other constituents such as bullet lubircant and primer residues. Bullet wipe occurs at any range of fire as long as the bullet has not passed through some intermediate object.

Range Shot and Range of Fire: The distance a shot is fired from muzzle to target.

Intermediate Range Shot: Shot fired at a muzzle-to-substrate distance sufficient to produce powder stippling (skin) or deposition (inanimate objects).

ACP: Automatic Colt Pistol

BHE: Bullet Hole Entry

About the Authors

John Louis Larsen served as a Special Agent for 22 years and was one of the founders of the FBI’s Evidence Response Team (ERT) program. His last duty assignment was to the FBI’s Chicago Division as Senior Team Leader. He is currently president of Larsen Forensics, Inc. and a forensics instructor at the Suburban Law Enforcement Academy at the College of DuPage in Glen Ellyn, Illinois. He can be reached at:
630-418-0031
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www.larsenforensicsinc.com

Arthur H. Borchers is a sergeant with the Oak Park Police Department for the last 30 years. His skill levels include Department Range Master, Armorer, Detective, Evidence Technician, and Traffic Crash Reconstructionist. He holds an ACTAR (Accreditation Commission for Traffic Accident Reconstruction). Borchers can be reached at:
708-267-8115
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References and Suggested Reading

Di Maio, V. J., Gunshot Wounds Practical Aspects of Firearms, Ballistics, and Forensic Techniques. CRC Press Inc.: 1993.

Fisher, B., Techniques of Crime Scene Investigation (Seventh Ed.). CRC Press: 2004.

Gardner, R., Bevel, T., Practical Crime Scene Analysis and Reconstruction. CRC Press Inc.: 2009.

Haag, L. C., Shooting Incident Reconstruction. Elsevier Inc.: 2006.
Spitz, W. U., Medicolegal Investigation of Death: Guidelines for the Application of Pathology to Crime Investigation (Third Ed.). Thomas Books: 1993.

 
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