A comparison microscope, sometimes known also as stereomicroscope or dissecting microscope, is a device used to analyze side-by-side specimens. It consists of two microscopes connected to an optical bridge, which results in a split view window. The comparison microscope is used in forensic sciences to compare microscopic patterns and identify or deny their common origin. The idea behind the comparison microscope is simple. Two microscopes are placed next to each other and the optical paths of each microscope are connected together by the optical bridge would help the forensic examiners to simultaneously compare two specimens instead of depending their memory. ... A microscope (Greek: micron = small and scopos = aim) is an instrument for viewing objects that are too small to be seen by the naked or unaided eye. ... Crime Scene, done by the United States Army Criminal Investigation Command Forensic science (often shortened to forensics) is the application of a broad spectrum of sciences to answer questions of interest to the legal system. ...

Forensic Ballistics

Main article: ballistics

Mel Sobel KT-1922 Comparison Microscope

Handguns predominated as the firearm of choice in shooting-related crimes, especially in the United States of America. As with most firearms, the fired ammunition components may acquire sufficient unique and reproducible microscopic marks to be identifiable as having been fired by a single firearm. Making these comparisons is correctly referred to as firearms identification, or sometimes called as “ballistics”. Historically, and currently, this forensic discipline ultimately requires a microscopic side-by-side comparison of fired bullets or cartridge cases, one pair at a time, by a forensic examiner to confirm or possibly eliminate the two items as having been fired by a single firearm. For this purpose, the traditional tool of the firearms examiner has been what is often called the ballistics comparison microscope. Comparison microscope is essential for the forensic ballistics expert in comparing bullets and spent cartridge casings. The interior of a gun’s barrel is machined to have grooves that force the bullet to rotate as it travels along it. These grooves and their counterpart, called “lands” imprint groove and land impressions on the surface of the bullet. Together with these land and groove impressions, imperfections on the barrel surface are incidentally transferred to the bullet’s surface. Because these imperfections are randomly generated, during manufacture or due to use, they are unique to each barrel. These patterns or imperfections, therefore, amount to a “signature” that each barrel imprints on each of the bullets fired through it. It is this “signature” on the bullets imparted due to the unique imperfections on the barrel that enable the validation and identification of bullets as having originated from a particular gun. Comparison microscope is used to analyze the matching of the microscopic impressions found on the surface of bullets and casings. Ballistics (gr. ... A handgun is a firearm small enough to be carried and used in one hand. ... An assortment of modern hand-held firearms using fixed ammunition, including military assault rifles, a sporting shotgun (fourth from bottom), a tactical shotgun (third from bottom), and a sporting rifle (top). ... Boxes of ammunition clog a warehouse in Baghdad Ammunition is a generic military term meaning (the assembly of) a projectile and its propellant. ... In the field of forensic science, forensic ballistics is the science of analyzing firearm usage in crimes. ... .357 Magnum cartridges, containing bullets A bullet is a solid projectile propelled by a firearm and is normally made from metal (usually lead). ... A M4 Carbine just after firing, with an ejected case in mid-air The article titled casing is a disambiguation page. ... Ballistics (gr. ... This article does not cite its references or sources. ...

When a firearm or a bullet or cartridge case are recovered from a crime scene, forensic examiners compare the ballistic fingerprint of the recovered bullet or cartridge case with the ballistic fingerprint of a second bullet or cartridge case test-fired from the recovered firearm. If the ballistic fingerprint on the test-fired bullet or cartridge case matches the ballistic fingerprint on the recovered bullet or cartridge case, investigators know that the recovered bullet or cartridge case was also fired from the recovered gun. A confirmed link between a specific firearm and a bullet or cartridge case recovered from a crime scene constitutes a valuable lead, because investigators may be able to connect the firearm to a person, who may then become either a suspect or a source of information helpful to the investigation. A crime scene is a location where an illegal act took place such as molestation, rape or illegal turnip smoking, and comprises the area from which most of the physical evidence is retrieved by [[forensics|forensic scientists] for example the reknowned criminal investigator and skilled forensic scientist, who is unfortunately... Ballistic fingerprinting, a sub-category of firearms examination, is a forensic method that is intended help to find the gun that was used in a crime by matching the bullets striations (or striae) with the rifled barrel through which it was fired, or by matching marks on the cartridge...

Sacco and Vanzetti Case

Main article: Sacco and Vanzetti

Forensic innovator Calvin Goddard offered ballistic identification evidence in 1921 to help secure convictions of accused murderers and anarchists Nicola Sacco and Bartolomeo Vanzetti. On April 8, 1927, Sacco and Vanzetti were finally sentenced to death in the electric chair. A worldwide outcry arose and Governor Alvin T. Fuller finally agreed to postpone the executions and set up a committee to reconsider the case. By this time, firearms examination had improved considerably, and it was now known that an automatic pistol could be traced by several different methods if both bullet and casing were recovered from the scene. Automatic pistols could now be traced by unique markings of the rifling on the bullet, by firing pin indentations on the fired primer, or by unique ejector and extractor marks on the casing. The committee appointed to review the case used the services of Calvin Goddard in 1927. Goddard used Philip Gravelle's newly-invented comparison microscope and helixometer, a hollow, lighted magnifier probe used to inspect gun barrels, to make an examination of Sacco’s .32 Colt, the bullet that killed Berardelli, and the spent casings recovered from the scene of the crime. In the presence of one of the defense experts, he fired a bullet from Sacco's gun into a wad of cotton and then put the ejected casing on the comparison microscope next to casings found at the scene. Then he looked at them carefully. The first two casings from the robbery did not match Sacco’s gun, but the third one did. Even the defense expert agreed that the two cartridges had been fired from the same gun. The second original defense expert also concurred. The committee upheld the convictions. In October 1961, ballistics tests were run with improved technology using Sacco's Colt automatic. The results confirmed that the bullet that killed the victim, Berardelli in 1920 came from the same .32 Colt Auto taken from the pistol in Sacco's possession. Subsequent investigations in 1983 also supported Goddard's findings. Nicola Sacco (right) and Bartolomeo Vanzetti in handcuffs Nicola Sacco (April 22, 1891 – August 23, 1927) and Bartolomeo Vanzetti (June 11, 1888 – August 23, 1927) were two Italian-born American anarchists, who were arrested, tried, and executed via electrocution in Massachusetts. ... Year 1921 (MCMXXI) was a common year starting on Saturday (see link for full calendar). ... Sacco (right) and Vanzetti Nicola Sacco (1891 - August 23, 1927) and Bartolomeo Vanzetti (1888 - August 23, 1927) were two Italian anarchists, who were arrested, tried, and executed in Massachusetts in the 1920s on charges of murder of a shoe factory paymaster named Frederick Parmenter and a security guard named Alesandro... Sacco (right) and Vanzetti Nicola Sacco (1891 - August 23, 1927) and Bartolomeo Vanzetti (1888 - August 23, 1927) were two Italian anarchists, who were arrested, tried, and executed in Massachusetts in the 1920s on charges of murder of a shoe factory paymaster named Frederick Parmenter and a security guard named Alesandro... April 8 is the 98th day of the year in the Gregorian calendar (99th in leap years). ... 1927 (MCMXXVII) was a common year starting on Saturday (link will display full calendar). ... The electric chair is an execution method in which the person being killed is strapped to a chair and electrocuted through electrodes placed on the body. ... A semi-automatic pistol is a handgun commonly used as a sidearm by police and military all over the world. ... .357 Magnum cartridges, containing bullets A bullet is a solid projectile propelled by a firearm and is normally made from metal (usually lead). ... A M4 Carbine just after firing, with an ejected case in mid-air The article titled casing is a disambiguation page. ... The firing pin is a very hard steel rod with a one small, rounded end for striking the primer of a cartridge. ... An extractor is a holding device, that holds onto the rim of ammunition, as to eject the empty casing when cycling after a shot has been fired. ... 1927 (MCMXXVII) was a common year starting on Saturday (link will display full calendar). ... This article does not cite its references or sources. ... 1961 (MCMLXI) was a common year starting on Sunday (the link is to a full 1961 calendar). ... 1920 (MCMXX) was a leap year starting on Thursday. ... 1983 (MCMLXXXIII) was a common year starting on Saturday of the Gregorian calendar. ...

St. Valentine’s Day Massacre

Main article: St. Valentine’s Day Massacre

Colonel Goddard was the key forensic expert in solving the 1929 St. Valentine's Day Massacre in which seven gangsters were killed by rival Al Capone mobsters dressed as Chicago police officers. It was also led to the establishment at Northwestern University, United States’ first independent criminological laboratory, which Goddard headed, and where ballistics, fingerprinting, blood analysis and trace evidence where brought under one roof. In 1929, using a comparison microscope adapted for the ballistics comparison by his partner, Phillip Gravelle, Goddard used similar techniques to absolve the Chicago Police Department of participation in the St. Valentine’s Day Massacre. ^[1] The case of Sacco and Vanzetti, which took place in Bridgewater, Massachusetts, is responsible for popularizing the use of the comparison microscope for bullet comparison. Forensic expert Calvin Goddard’s conclusions were upheld when the evidence was reexamined in 1961. Valentines Day Massacre may refer to many different things: History St. ... 1929 (MCMXXIX) was a common year starting on Tuesday (link will take you to calendar). ... Picture of The St. ... “Capone” redirects here. ... Mobster is a slang term for a person who participates in organized crime, which is known as belonging to the Mob. In western stories and movies, cowboys as mobsters are known as outlaws. ... Municipal Flag of the City of Chicago The Chicago Police Department, also known as the CPD, is the principal law enforcement agency of Chicago, Illinois, under the jurisdiction of the mayor of Chicago. ... Northwestern University is a private, coeducational, non-sectarian research university, located in Evanston and Chicago, Illinois. ... Ballistics (gr. ... This article is about human fingerprints. ... Trace evidence is evidence that is found at a crime scene in small but measurable amounts. ... 1929 (MCMXXIX) was a common year starting on Tuesday (link will take you to calendar). ... Valentines Day Massacre may refer to many different things: History St. ...

History

The history of comparison microscope dated back to the 1920s where forensic ballistics was waiting for the inception. The controversial case of accused murderers and anarchists Nicola Sacco and Bartolomeo Vanzetti was such a beginning point. Comparison microscope was used for ballistic identification evidence in 1921 to help secure convictions of accused murderers Sacco and Vanzetti. In 1929, using a comparison microscope adapted for the purpose by Calvin Goddard and his partner Phillip Gravelle used similar techniques to absolve the Chicago Police Department of participation in the St. Valentine’s Day Massacre.

Col. Calvin H. Goddard

Main article: Calvin Goddard (Ballistics)

Goddard with Comparison Microscope

Philip O. Gravelle, a chemist, developed comparison microscope for use in the identification of fired bullets and cartridge cases with the support and guidance of forensic ballistics pioneer Calvin Goddard. It was a giant leap in the science of firearms identification in forensic science. The firearm from which a bullet or cartridge case has been fired is identified by the comparison of the unique striae left on the bullet or cartridge case from the worn, machined metal of the barrel, breach block, extractor, or firing pin in the gun. It was Gravelle who mistrusted his memory. "As long as he could inspect only one bullet at a time with his microscope, and had to keep the picture of it in his memory until he placed the comparison bullet under the microscope, scientific precision could not be attained. He invented the comparison microscope and Goddard made it work." Calvin Goddard perfected the comparison microscope for use in bullet and cartridge case comparison and popularized it. ^[2]Sir Sydney Smith also appreciated the idea, emphasizing the importance of stereo-microscope in forensic science and firearms identification. He took the comparison microscope to Scotland and introduced it to the European scientists for firearms identification and other forensic uses. A chemist pours from a round-bottom flask. ... This article is about the projectile, for other uses see bullet (disambiguation). ... A M4 Carbine just after firing, with an ejected case in mid-air The article titled casing is a disambiguation page. ... A firearm is a kinetic energy weapon that fires either a single or multiple projectiles propelled at high velocity by the gases produced by action of the rapid confined burning of a propellant. ... Crime Scene, done by the United States Army Criminal Investigation Command Forensic science (often shortened to forensics) is the application of a broad spectrum of sciences to answer questions of interest to the legal system. ... This article does not cite its references or sources. ... An extractor is a holding device, that holds onto the rim of ammunition, as to eject the empty casing when cycling after a shot has been fired. ... The firing pin is a very hard steel rod with a one small, rounded end for striking the primer of a cartridge. ... A gun is a common name given to an object that fires high-velocity projectiles. ... Motto (Latin) No one provokes me with impunity Cha togar mfhearg gun dioladh (Scottish Gaelic)1 Wha daur meddle wi me?(Scots)1 Anthem (Multiple unofficial anthems) Scotlands location in Europe Capital Edinburgh Largest city Glasgow Official languages English, Gaelic Government Constitutional monarchy  -  Queen Queen Elizabeth II  -  Prime...

The Present

During the 1960s there were proposals to somehow “computerize” the process of microscopic comparisons of fired ammunition components, but at that time neither the software nor the hardware existed to implement the theories. By the 1980s that situation had changed radically, as represented by high-capacity computer systems adapted to the requirements of digital imaging, pattern recognition, image storage and comparison algorithms. Cooperation between private industry, law enforcement and forensic subject matter experts lead to the evolution of the Integrated Ballistics Identification System (IBIS™), now the preeminent system. It is deployed worldwide by Forensic Technology, Incorporated (FTI) of Montreal. ^[3] The 1960s decade refers to the years from January 1, 1960 to December 31, 1969, inclusive. ... Boxes of ammunition clog a warehouse in Baghdad Ammunition is a generic military term meaning (the assembly of) a projectile and its propellant. ... The 1980s refers to the period where corey sucks peters and has a not little to look at his little penis of and between 1980 and 1989. ... Digital imaging or digital image acquisition is the creation of digital images, typically from a physical object. ... For the band, see The Police. ...

Modern Comparison Microscope

Comparison of microscope has evolved since the mid-1920s Sacco and Vanzetti Case into an instrument with many optical, mechanical and electronic refinements, including fiber optic illumination, video capabilities, digital imaging, automatic exposure for conventional photography, etc. Despite this evolution, however, the basic tools and techniques have remained unchanged in their essential details which are to determine whether or not ammunition components were fired by a single firearm based on a sufficiency of unique and reproducible microscopic and class characteristics, or to reach a “no conclusion” result if insufficient marks are present. ^[4] The 1920s is a decade that is sometimes referred to as the Jazz Age or the Roaring Twenties, usually applied to America. ... Nicola Sacco (right) and Bartolomeo Vanzetti in handcuffs Nicola Sacco (April 22, 1891 – August 23, 1927) and Bartolomeo Vanzetti (June 11, 1888 – August 23, 1927) were two Italian-born American anarchists, who were arrested, tried, and executed via electrocution in Massachusetts. ... See also list of optical topics. ... The word mechanical can mean one of several things: A device or principle described as mechanical relates to a mechanism or machine, or the realm of Newtonian mechanics. ... Look up Electronic in Wiktionary, the free dictionary. ... An assortment of modern hand-held firearms using fixed ammunition, including military assault rifles, a sporting shotgun (fourth from bottom), a tactical shotgun (third from bottom), and a sporting rifle (top). ...

Since, ballistic identification has benefited from a long series of structural, scientific and technological advances, law enforcement agencies have established forensic labs and researchers have learned much more about how to match bullets and cartridge cases to the guns used to fire them, and comparison microscopes have become more sophisticated. By the end of the 1980s, ballistic identification was an established subspecialty of forensic science. Modern comparison microscope combines the latest opto-mechanical developments in light microscopy with ease of use and ergonomics, which allows the forensic examiner to achieving results with highest accuracy and efficiency. The comparison microscope like Leica FS4000 allows highly precise comparison of two objects at magnification up to 1500x and gives reliable proof of slightest differences in the microstructure, texture and colour. Mel Sobel KT-1922 is microscope is good also for class room teaching of forensics or and other sciences. It allows side by side comparisons of two slides as well as the ability to view each slide individually. Intelligent Automation Inc., an American Research and Development firm, has developed and implemented a visualization tool called the “Virtual Comparison Microscope” that allows the firearms examiner to verify the degree of similarity between any two tool-marks in question. The Virtual Comparison Microscope was designed to simulate the operation of the comparison microscope commonly used by firearms examiners. It is capable of rendering a 2D view of the 3D surfaces in a manner similar to that of the comparison microscope. It also enables the examiner to translate one tool mark or striae with respect to the other, overlap them, modify illumination conditions, zoom in and out, adjust the point of view of the user, and even provides the ability to create a split image on the screen that includes a hair-line to demarcate one tool-mark on the left of the screen from the other on the right. .357 Magnum cartridges, containing bullets A bullet is a solid projectile propelled by a firearm and is normally made from metal (usually lead). ... A M4 Carbine just after firing, with an ejected case in mid-air The article titled casing is a disambiguation page. ... The 1980s refers to the period where corey sucks peters and has a not little to look at his little penis of and between 1980 and 1989. ... Crime Scene, done by the United States Army Criminal Investigation Command Forensic science (often shortened to forensics) is the application of a broad spectrum of sciences to answer questions of interest to the legal system. ...

The Virtual Comparison Microscope allows for all the viewing conditions to be same for both tool-marks, and it does not require the adjustment of either the independent illumination or the focus of the tool-marks. Other unique characteristics of the Virtual Comparison Microscope include its ability to simulate any material or “palette” which may be useful to the user as well as adjustment of the angle of incidence of the light and the light intensity that can assist in emphasizing certain features in the 3-D images for better visualization. Some of the capabilities of the Virtual Comparison Microscope have no counterpart in a conventional comparison microscope. The Integrated Ballistics Identification System (IBIS™) system, developed by Forensic Technology, of Montreal, is a modern configuration of BulletTRAX™-3D paired with MatchPoint Plus™. This integrated system allows for image data entry, storage in a server and correlations (comparison of surface topography) between new and stored bullet image data. Search results are ranked and images are made available to examiners for preliminary evaluations prior to actual microscopic examinations. The Latest Configuration of IBIS BulletTRAX-3D combined with MatchPoint Plus is now being offered by Forensic Technology Inc., as an advanced technical solution for case linkage using fired bullets recovered at shooting scenes and from shooting victims. This integrated workstation is designed as a tool for the firearms examiner in preparing for the ultimate procedure, the physical microscopic intercomparison of fired bullets. The system as a whole takes advantage of the strength of computer technology by making massive numbers of eliminations of bullets from previously entered cases as candidates for physical comparison and potential case linkage with a bullet from a current case. It then combines that information with the ability of the human examiner to make the final decisions regarding those relatively few candidates selected by the system for the examiner’s consideration and possible microscopic comparison. ^[5]IBIS® ,Integrated Ballistics Identification System, is currently used by forensic examiners over 30 countries and territories.^[6] BulletTRAX-3D revolutionized the way bullet evidence is analyzed, and many forensic experts believe that this technology will eventually replace the comparison microscope. ^[7] Integrated Brass TRAX-3D, a device designed to allow investigators to capture and examine both three-dimensional and two dimensional images f cartridge cases. The BrassTRAX-3D and the BulletTRAX-3D bullet imaging device to form the IBIS-TRAX 3D line of ballistics identification systems. The IBIS - TRAX 3D line is designed to suggest possible matches between pairs of spent bullets and cartridge cases. The system is also engineered to include three-dimensional image viewing tools, modular flexibility, and higher automation. ^[8]

In the 1990s, computers joined comparison microscopes as essential tools of forensic examination. With advances in digital imaging technology and data storage capacity, forensic examiners envisioned a centralized database of images of bullets and cartridge cases that could be compared against a bullet or cartridge case recovered from a crime scene. By the mid 1990s, two such systems emerged. ^[9] The first system, developed by the Federal Bureau of Investigation (FBI), was called “Drugfire.” Drugfire used imaging software to capture, catalog and compare digital images of cartridge cases, bullets were added later. A forensic examiner would capture an image of a recovered bullet or cartridge and compare it with similar images from the database. Drugfire enabled the examiner to see many images of potential matches on one screen, greatly speeding up the process. However, Drugfire did not rank the images by how close a match they were, leaving that determination entirely to the examiner. More than 170 law enforcement agencies nationwide participated in the Drugfire program. The second system, developed by the Bureau of Alcohol, Tobacco and Firearms (ATF), was originally called “Ceasefire.” Like Drugfire, Ceasefire used imaging software to capture images of the markings on bullets and included a sophisticated comparison algorithm that automatically identified likely matches. Rather than requiring the examiner to sift through dozens or hundreds of images, the computer presented the examiner with a ranked list of the most likely matches. When the ATF expanded Ceasefire to include cartridge cases, it renamed the program the Integrated Ballistics Identification System (IBIS). In 1997, the ATF and the FBI agreed to try to combine Drugfire and IBIS to reduce the cost and inefficiency of maintaining both systems. However, technical obstacles prevented integrating the systems, sparking a pitched battle for supremacy. supporters of the FBI’s Drugfire system preferred its imaging technology and the degree of control they retained, while supporters of ATF’s IBIS system praised its automation and speed. After several years of wrangling, a compromise emerged. The new system would adopt IBIS’s imaging technology and comparison algorithms while relying on the FBI’s telecommunications network. Although a few devotees continued to use Drugfire on their own, IBIS became the standard centralized system. The National Integrated Ballistic Information Network (NIBIN) was born. ^[10] For the band, see 1990s (band). ... .357 Magnum cartridges, containing bullets A bullet is a solid projectile propelled by a firearm and is normally made from metal (usually lead). ... A M4 Carbine just after firing, with an ejected case in mid-air The article titled casing is a disambiguation page. ... A crime scene is a location where an illegal act took place such as molestation, rape or illegal turnip smoking, and comprises the area from which most of the physical evidence is retrieved by [[forensics|forensic scientists] for example the reknowned criminal investigator and skilled forensic scientist, who is unfortunately... The Federal Bureau of Investigation (FBI) is a federal criminal investigative, intelligence agency, and the primary investigative arm of the United States Department of Justice (DOJ). ... The Federal Bureau of Investigation (FBI) is a federal criminal investigative, intelligence agency, and the primary investigative arm of the United States Department of Justice (DOJ). ... The Bureau of Alcohol, Tobacco, Firearms and Explosives (BATFE or ATFE) is a law enforcement agency within the United States Department of Justice. ... ATF is a three-letter abbreviation that can stand for: ATF Hire Group [1], parent company of Australian Temporary Fencing, Aotearoa Temporary Fencing and Deck Guardrail Australia. ... 1997 (MCMXCVII) was a common year starting on Wednesday of the Gregorian calendar. ... ATF is a three-letter abbreviation that can stand for: ATF Hire Group [1], parent company of Australian Temporary Fencing, Aotearoa Temporary Fencing and Deck Guardrail Australia. ... The Federal Bureau of Investigation (FBI) is a federal criminal investigative, intelligence agency, and the primary investigative arm of the United States Department of Justice (DOJ). ...

References

External links

• BulletTRAX-3D
• Virtual Comparison Microscope
• Forensic Technology