Comparative bullet-lead analysis
Encyclopedia
Comparative bullet-lead analysis (CBLA) also known as Compositional bullet-lead analysis) is a now discredited and abandoned forensic technique which used chemistry
to link crime scene
bullet
s to ones possessed by suspects on the theory that each batch of lead
had a unique elemental makeup.
The technique was first used after U.S. President John F. Kennedy
's assassination in 1963. From the early 1980s through 2004 the US Federal Bureau of Investigation
conducted about 2,500 analyses on cases submitted by law-enforcement groups. The results of these analyses had often been questioned by defense lawyers and the press, so the FBI finally asked the United States National Academy of Science's Board on Science, Technology, and Economic Policy
to research the scientific merit of the process.
In 2004 the Board's study was summarized in "Forensic Analysis: Weighing Bullet Lead Evidence." The Board determined that the chemical analyses were being performed correctly and were probably sufficient to determine correlation between two bullets from separate sources (the analysis used plasma-optical emission spectroscopy
to identify trace elements in the bullets). The report also concluded that the seven trace elements selected for the analyses (arsenic, antimony, tin, copper, bismuth, silver and cadmium) are acceptable for sample correlation. The report finally concluded that the procedure is the best available method for such correlations. The greatest caveat
in the report was that the statistical
tests as applied by the FBI could cause confusion and misinterpretation when transmitted to prosecutors or when explained to a trial jury. Because of the significance of this weakness, the report concluded that the analysis should be used with caution. This report helped the FBI decide in 2004 to voluntarily cease offering the analysis to law-enforcement entities. The National Academy of Sciences never required that the FBI stop using the test.
CNN PRESENTS Encore Presentation: Reasonable Doubt examined the unreliability of this technique. It has been discontinued as of September 1, 2005.
The U.S. government has fought releasing the list of the estimated 2,500 cases over three decades in which it performed the analysis, which may have led to false convictions. According to the FBI, only 20% of the 2,500 tests performed introduced the CBLA results into evidence at trial.
In 17 December 2008, Jimmy Ates was released from a Florida prison after serving ten years on the conviction of having murdered his wife, a conviction obtained largely on the strength of a bullet-lead analysis. His conviction was overturned as a consequence of the 2004 report.
On March 10, 2011, Jimmy Ates was retried and convicted again of having murdered his wife. Despite initial reports that his first conviction had been obtained largely on the strength of bullet-lead analysis, this turned out to be untrue. The bullet-lead analysis was completely meaningless in his first as well as his second trial. The evidence of Jimmy Ates' guilt turned out to be overwhelming. He admitted in three (3) separate interviews to being inside his home when his wife made a 911 call. This was a call he was both unaware of and refused to believe had actually occurred. Additionally, seven (7) separate witnesses placed both of the Ates' vehicles at the home subsequent to the 911 call. A time-delayed device was then used to set a time-delayed fire by the front picture window of the Ates' residence which faced the busy main Highway 189 in Baker, Florida. The murder and the victim's body were at the other end of the home. The fire was reminiscent of those often seen in arson for profit cases where the arsonist needs an alibi. There was much more evidence presented of Jimmy Ates' guilt. Mr. Ates' case was attempted to be used by advocates as an example in hopes of over-turning other convictions. However, to date, there have been no other reported convictions that have been over-turned as a result of using bullet-lead analysis. Apparently, the original prosecutor who had agreed to over-turn the first conviction of Jimmy Ates without a hearing, and without consultation with law enforcement, the original prosecutors or the victim's family, announced his resignation during the second trial.
Chemistry
Chemistry is the science of matter, especially its chemical reactions, but also its composition, structure and properties. Chemistry is concerned with atoms and their interactions with other atoms, and particularly with the properties of chemical bonds....
to link crime scene
Crime scene
A crime scene is a location where an illegal act took place, and comprises the area from which most of the physical evidence is retrieved by trained law enforcement personnel, crime scene investigators or in rare circumstances, forensic scientists....
bullet
Bullet
A bullet is a projectile propelled by a firearm, sling, or air gun. Bullets do not normally contain explosives, but damage the intended target by impact and penetration...
s to ones possessed by suspects on the theory that each batch of lead
Lead
Lead is a main-group element in the carbon group with the symbol Pb and atomic number 82. Lead is a soft, malleable poor metal. It is also counted as one of the heavy metals. Metallic lead has a bluish-white color after being freshly cut, but it soon tarnishes to a dull grayish color when exposed...
had a unique elemental makeup.
The technique was first used after U.S. President John F. Kennedy
John F. Kennedy
John Fitzgerald "Jack" Kennedy , often referred to by his initials JFK, was the 35th President of the United States, serving from 1961 until his assassination in 1963....
's assassination in 1963. From the early 1980s through 2004 the US Federal Bureau of Investigation
Federal Bureau of Investigation
The Federal Bureau of Investigation is an agency of the United States Department of Justice that serves as both a federal criminal investigative body and an internal intelligence agency . The FBI has investigative jurisdiction over violations of more than 200 categories of federal crime...
conducted about 2,500 analyses on cases submitted by law-enforcement groups. The results of these analyses had often been questioned by defense lawyers and the press, so the FBI finally asked the United States National Academy of Science's Board on Science, Technology, and Economic Policy
Board on Science, Technology, and Economic Policy
The United States National Academy of Sciences' Board on Science, Technology, and Economic Policy is a board of the United States National Academy of Sciences....
to research the scientific merit of the process.
In 2004 the Board's study was summarized in "Forensic Analysis: Weighing Bullet Lead Evidence." The Board determined that the chemical analyses were being performed correctly and were probably sufficient to determine correlation between two bullets from separate sources (the analysis used plasma-optical emission spectroscopy
Atomic emission spectroscopy
Atomic emission spectroscopy is a method of chemical analysis that uses the intensity of light emitted from a flame, plasma, arc, or spark at a particular wavelength to determine the quantity of an element in a sample...
to identify trace elements in the bullets). The report also concluded that the seven trace elements selected for the analyses (arsenic, antimony, tin, copper, bismuth, silver and cadmium) are acceptable for sample correlation. The report finally concluded that the procedure is the best available method for such correlations. The greatest caveat
Caveat
Caveat , the third-person singular present subjunctive of the Latin cavere, means "warning" ; it can be shorthand for Latin phrases such as:...
in the report was that the statistical
Statistics
Statistics is the study of the collection, organization, analysis, and interpretation of data. It deals with all aspects of this, including the planning of data collection in terms of the design of surveys and experiments....
tests as applied by the FBI could cause confusion and misinterpretation when transmitted to prosecutors or when explained to a trial jury. Because of the significance of this weakness, the report concluded that the analysis should be used with caution. This report helped the FBI decide in 2004 to voluntarily cease offering the analysis to law-enforcement entities. The National Academy of Sciences never required that the FBI stop using the test.
CNN PRESENTS Encore Presentation: Reasonable Doubt examined the unreliability of this technique. It has been discontinued as of September 1, 2005.
The U.S. government has fought releasing the list of the estimated 2,500 cases over three decades in which it performed the analysis, which may have led to false convictions. According to the FBI, only 20% of the 2,500 tests performed introduced the CBLA results into evidence at trial.
In 17 December 2008, Jimmy Ates was released from a Florida prison after serving ten years on the conviction of having murdered his wife, a conviction obtained largely on the strength of a bullet-lead analysis. His conviction was overturned as a consequence of the 2004 report.
On March 10, 2011, Jimmy Ates was retried and convicted again of having murdered his wife. Despite initial reports that his first conviction had been obtained largely on the strength of bullet-lead analysis, this turned out to be untrue. The bullet-lead analysis was completely meaningless in his first as well as his second trial. The evidence of Jimmy Ates' guilt turned out to be overwhelming. He admitted in three (3) separate interviews to being inside his home when his wife made a 911 call. This was a call he was both unaware of and refused to believe had actually occurred. Additionally, seven (7) separate witnesses placed both of the Ates' vehicles at the home subsequent to the 911 call. A time-delayed device was then used to set a time-delayed fire by the front picture window of the Ates' residence which faced the busy main Highway 189 in Baker, Florida. The murder and the victim's body were at the other end of the home. The fire was reminiscent of those often seen in arson for profit cases where the arsonist needs an alibi. There was much more evidence presented of Jimmy Ates' guilt. Mr. Ates' case was attempted to be used by advocates as an example in hopes of over-turning other convictions. However, to date, there have been no other reported convictions that have been over-turned as a result of using bullet-lead analysis. Apparently, the original prosecutor who had agreed to over-turn the first conviction of Jimmy Ates without a hearing, and without consultation with law enforcement, the original prosecutors or the victim's family, announced his resignation during the second trial.