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Articles
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Examination
of firearm primers and gunpowders by scanning electron microscopy/energy dispersive x-ray analysis.
Observations by scanning electron microscopy/energy dispersive x-ray spectroscopy (SEM/EDS)
of unfired standard primer material (lead/antimony/barium) are presented from the centerfire cartridge primers
of Winchester, Speer and Remington. Also examined by SEM/EDS are the surfaces of thirty-two gunpowders (GPs) from
Winchester, Federal, Hercules, DuPont and Remington. Compounds of sulfur, potassium and barium as well as primer-like
particles composed of lead, antimony and barium were found on the surfaces of many of these GPs. The elements
of these compounds likely contribute to gunshot residue (GSR) generated by the discharge of a firearm. We introduce
the term, “hybrid GSR” which will account for both the contribution to primer GSR by the interior firearm surfaces
GSR and the elements associated with GP.
Staged Suicide:
A Southern United States Substitute for Lynching
Homicide Detection in a Cold Case Assisted by Image Processing
The official determination in 2008 of the manner of death
of the victim was by suicide with a 12 gauge shotgun to his left head at the ear. However, an examination of the
police reports, death scene images and autopsy images and report revealed a homicide occurred. This homicide is
unusual: 1) Blowback from a contact discharge to the victim's head was substantial, propelling tissue as much as
47 feet (14.3 m) from the victim. 2) The shotgun's position at discharge was not possible for the suicide scenario.
3) The crime scene was ineptly staged to appear that a suicide occurred. 4) The staging of the crime scene continued
into the scene processing. 5) Image processing by Adobe Photoshop was instrumental in determining the victim died
by homicide. 6) Multiple persons were involved in the homicide.
The Flechtner Shooting: Self
Defense or Murder?
This report analyzes and reconstructs the shooting of
three persons in the driveway at 4554 Begonia Road, Phelan California on October 4, 2009 at approximately 1945
hrs. Phelan is a high desert community with no paved roads near the city of Victorville, California. Dennis Flechtner,
was the shooter and the deceased were Adam Owen, Robert Light and Angela Leird. There was a single witness to the
shooting, Whitney Telliano. The shooting was the culmination of a twelve-year dispute between neighbors Flechtner
and Leird. Flechtner was charged with three counts of first degree murder. The reconstruction assisted the jury
in coming to a decision of "not guilty" for all three counts.
People v. Jackson Daniels:
The shooting of Riverside Police Officers Dennis Doty and Phillip Trust
Officers Dennis Doty and Phillip Trust entered a residence
in Riverside, California to arrest Jackson Daniels, a wheel chair-confined felon. Upon entering the house, both
Doty and Trust were involved in an exchange of gunfire with Daniels. Fifteen shots were fired with three .38 revolvers.
Officer Doty lost his life within seconds of the start of the shooting. But the wounded Officer Trust interacted
with his assailant and the crime scene for a number of minutes after the death of Officer Doty. The interaction
between Daniels and Trust during these minutes created a complex crime scene which due to an error in the prosecution�s
reconstruction (selection the wrong wound as the first suffered by Trust) left the interpretation of the scene
confused.
Selection of the correct first wound for Trust and an understanding of the consequence of that wound allow for
the presentation of a scenario that connects most features of the entire crime scene. The results of this analysis
make it clear that Jackson Daniels was relentless in his quest to kill Trust and he took a thoughtful and patient
approach to achieve that goal.
Under Scale Deposition
of Gunshot Residue in Head Hair
This study shows that the victim was shot in the head
with the pistol�s muzzle at intermediate range. Due to probable post shooting handling, the
gunshot residue (GSR) was lost from the surface of the hair that was collected from around the victim�s
head wound. It is shown in this study that the pistol discharge was close enough to cause cuticular hair scales
to be lifted, but not removed, in the muzzle blast and GSR inserted under the scales. The GSR under the cuticular
scales was thus protected from mechanical and chemical removal. The number and form of the GSR particles observed
from the victim�s hair sample when compared to the observations from test shot hair indicate
that the firearm �s muzzle could have been as close as 6 inches but not further than 12 inches.
Documentation of the
Discharge of a .380 Pistol Within a Vehicle
This case involves the alleged single discharge of a .380
pistol within a
vehicle and documenting the GSR burden on interior surfaces of a similar car resulting from such a discharge.
Examination of a 30+ Year-Old Shooting Death with a Ruger .44 Magnum Carbine That Has No Remaining Physical Evidence
The victim sustained a fatal bullet to the head from a
Ruger .44 Magnum Carbine (18.5-inch barrel length) in 1973. The shooter was the victim�s husband
who claimed the rifle accidentally discharged while he was cleaning the newly-purchased rifle. At the time, the
shooting was determined to be accidental. No physical evidence remains of this shooting with only the autopsy report
and a small number of shooting scene photographs. In 2006, that same shooter was accused of the shooting death
of his most recent wife. The 1973 shooting was re-filed as murder. The characteristics of the Ruger .44 Magnum
Carbine are examined in this study as to partially-burned powder discharge from the muzzle as well as sooting of
close targets.
Investigation of the shooting
of teenager Christopher St. Louis
The shooting of teenager Christopher St. Louis by off-duty
police officer Tanaya Webb at the Santee, California Petco shopping center the evening of February 16, 2003 is
examined. Four shots were fired in one second with a Glock Model 27, .40 caliber pistol and St. Louis received
four wounds: left chest, right chest, lower right abdomen and right arm. He died minutes after being shot. St.
Louis was shot while running towards Webb. The shooting scene reconstruction indicates that St. Louis received
the first shot approximately 27 feet and the last shot when he was approximately 15 feet from Webb.
Investigation of the
death of Colonel James Sabow, USMC
The investigation of the circumstances of the death of
Colonel James E. Sabow is continued in this report. The extraordinary quality of the photographs of the crime scene
and autopsy was instrumental for this examination. Evaluation of the gunshot residue, back spatter residue, cranial
injuries, blood spatter, the Colonel s bathrobe and the position of the body lead to the conclusion that Colonel
James Sabow was murdered and an attempt was made to stage the body to appear that he committed suicide. The Colonel
was rendered unconscious and mortally wounded by a devastating blow by a broad, flat club to the right occipital
region of his skull prior to the intraoral shotgun blast. The reconstruction of the homicide crime scene indicates
that three or more assailants were likely.
The Bizarre Case of People
v. Contreras
The victim died from a single.22 bullet wound to the chest
that came through a window and the victim's girlfriend was accused of the homicide. This case has been published
(B.R.Burnett, Journal of Forensic Sciencses. 2001. 46(2):379-385). The purpose of this article is to reexamine
the extraordinary nature of the physical evidence of this case and discuss the testimony of three experts who testified
in one or more of the three trials of People v. Delia Contreras.
Lead in House and Automotive
Keys
Concentrations of lead in keys, both old and new are reported.
A health risk exists for the entire population, not only for locksmiths/key makers. Small children may have significant
lead exposure, especially for those children that put keys in their mouths.
Gunshot residue samplers from suspects in shooting cases should not be reported as having particles "consistent
with gunshot residue" when the only particles found are lead. A significant environmental source of lead particles
in gunshot residue samplers is likely from house and automotive keys.
The Gunshot Residue Evidence of
People v. Robert Blake: A Case of Forensic Alchemy
The gunshot residue evidence in the case of People v.
Robert Blake is presented. Automated scanning electron microscopes (SEM) equipped with elemental analyzers (energy
dispersive X-ray spectroscopy, EDS) were used to find and identify presumptive gunshot residue particles from the
evidence. Errors were made in the handling of Mr. Blake after the shooting, testing the murder weapon, testing
Mr. Blake's revolver, storage of Mr. Blake's clothing, interpretation of spectra from almost all of the analyses
and the assignment of particles as "consistent" or "highly specific" to gunshot residue. In
addition, the gunshot residue reports fail to distinguish between individual and populations of particles, a critical
distinction considering virtually all elemental combinations of lead, antimony and barium found in gunshot residue
may also originate from environmental sources. A limited evaluation of the testimony by the defense expert is presented.
Mr. Steven Dowell of the Los Angeles County Department of the Coroner provided a summary on this case at the Scanning
2005 meeting (April 7, 2005, Monterey, California). A transcript of Mr. Dowell's talk is attached to this article.
22 Rimfire Ammunition
Antimony
Coats Many .22 Caliber Bullets
Macro
Imaging with a Digital Camera: Examination of a .22 Revolver
The Pixera 600CL, a 5.8 megapixel peltier cooled CCD camera,
when attached to a macro zoom lens can be stopped down > f 44. This allows for extraordinary depth of field
of objects up to ~ 15X that match or exceed that of the scanning electron microscope.
Nose or Base Strike
Analysis of Bullet Orientation in a Ricochet
Observations on the Composition of Breech Gunshot Residue from a .22 pistol
People v.
Aceves: A Case of 22 Caliber Gun Shot Residue Matching
This is the analysis of a shooting where the assailant
shot the victim twice with a .22 revolver. The ammunition was Remington with a single metal primer. The weapon
attributed to the shooting is shown to have likely last fired Federal three-metal primered ammunition and thus
could not have been the weapon used in the shooting. This paper examines the effect of previous-shot gunshot residue
(GSR) contamination as well as the GSR compositional differences in samples from the breech, target and bore. This
work also shows that the accumulation of GSR within a .22 revolver, especially from different ammunitions, makes
the resultant GSR composition from a shot unpredictable. The antimony that covers most modern .22 bullets is likely
to contribute substantial amounts of antimony to the GSR of some shots.
Failure of
a Security System Due to Motion Sensor Cover Failure
Six security motion devise covers were received for analysis
following apparent failure of the security system in a tire/brake store burglary. Four of the covers of these thin
plastic sheets were from failed devices and two were controls. The control covers were from devices that operated
normally. The covers were examined by normal light, ultraviolet light transmittance and scanning electron microscopy/elemental
analysis. The submitting party suspected that some sort of material was sprayed on these covers, rendering them
inoperative. The results of these analyses indicated no evidence of human manipulation. Rather, it is apparent
that environmental factors likely caused the degradation of the plastic covers which resulted in the failure to
allow the radiation specific to the motion detector to pass through.
Skin Debris
and Gunshot Residue Samplers: I. The Particle Habitus
A series of experiments were performed to determine how
skin debris (desquamated epithelial cells and skin oils) affects gunshot residue (GSR) particle detection on SEM
stubs: 1) A dabbing experiment showed that GSR particles accumulate not only on the adhesive surface of the sampler,
but also on the epithelial cells. 2) A bleach solution made up of sodium and calcium hypochlorite was used to remove
skin debris from gunshot residue samplers. This bleach treatment revealed particles that were originally hidden
by skin debris. Skin debris not only accumulates GSR particles, but also obscures particles.
Skin Debris and Gunshot
Residue Samplers: II. The Issue of Acceleration Voltage
A sampler was initially loaded with target gunshot residue
(GSR) and then was dabbed 30 times on the back of a hand. A number of high-resolution (4096 x 4096 pixel) backscatter
images were taken at 20 kV and then at 30 kV of the same areas. Following these images, the sampler was treated
to remove skin debris with a sodium/calcium hypochlorite solution and additional high-resolution images were taken
at 20 kV of the same areas. Comparison of these images shows that more GSR particles are revealed at 30 kV than
at 20 kV. The removal of skin debris evinced even more GSR particles that were not detected on the untreated samplers,
regardless of the acceleration voltage used.
Errors
in gunshot residue assessment by scanning electron microscopy/elemental analysis in criminal cases: I. Arsenic/sulfur
mistaken for lead.
Automated scanning electron microscope analyses of gunshot
residue samplers are being performed by many crime laboratories all over the world. Often the criminalist-technician
operators of these instruments do not have adequate training for the interpretation of spectra generated by energy
dispersive X-ray spectroscopy. Case 1 is an example of this. Case 2 is an example of a criminalist who appeared
to have misrepresented the elemental composition of a particle in order to make it "unique" to gunshot
residue. This article is the first in a series of four articles that will focus on erroneous elemental assignments
and/or missed elements made by ill-trained criminalists. The mistaken assignments of particle spectra to "consistent,"
"highly specific" or "unique" gunshot residue will also be examined in this article series.
Errors in gunshot residue
assessment by scanning electron microscopy/elemental analysis in criminal cases: II. Missed tin (Sn) and antimony
(Sb) in an unusual, non-gunshot residue population of particles containing phosphorus (P).
Automated scanning electron microscope analyses of gunshot
residue samplers are being performed by many crime laboratories all over the world. Often the criminalist-technician
operators of these instruments do not have adequate training for the interpretation of spectra generated by energy
dispersive X-ray spectroscopy. In this case, a number of unusual particles, most of which contain phosphorus (P)
and tin (Sn) were assigned by the criminalist as being "unique" to gunshot residue. Unfortunately, none
of the particle spectra recorded in this case can even be assigned as "consistent," much less "unique"
to gunshot residue. Errors made by this technician are 1) missed elements, tin (Sn) and antimony (Sb), and 2) including
phosphorus (P) as a gunshot residue element. The origin of these particles is unknown.
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