On October 18,1980 Joseph A. Reitz and Alfred M. Woolridge. Supervisors of the Firearms Identification and latent Fingerprint Units, laboratory Division, were presented plaques of appreciation for their participation as lecturers at the Fall Seminar, Maryland Shorthand Reporters Association held at Easton, Maryland. Pictured are, left to right, Joseph A. Reitz, Alfred M. Woolridge, Mr. Bud Felkowski, President, Maryland Shorthand' Reporters Association and Joseph V. Lanzetta, laboratory Division, Examination Section Supervisor.

Firearms, bullets, cartridge casings

Forensic science involves the application of hard science and technology to the solution and prosecution of crime. Based upon the underlying principle that the criminal leaves part of himself at the scene, and takes part of the crime site with him, forensic science includes the identification and analysis of physical evidence in the form of impressions, trace evidence, and weaponry. Since physical evidence needs to be interpreted by an expert, it is, by definition, circumstantial. Fields of forensic science include: fingerprint technology, scientific lie detection, firearms identification, questioned documents, and forensic pathology, toxicology, chemistry, botany, entomology, anthropology, geology, and serology (DNA).

In 1901, Scotland Yard became the first law enforcement agency in the work to routinely fingerprint its arrestees. Fingerprint identification came to America in 1904 when the St. Louis Police Department established its fingerprint bureau. Before fingerprinting, arrestees were identified by sets of eleven body measurements, a system created in the 1870's by the Frenchman, Alphonse Bertillon. By 1914, the year of Bertillon's death, fingerprinting had replaced anthropometry or Bertillonage in every country except America where, in many jurisdictions, the outdated system was used until the 1920's.

Because a set of inked, rolled-on fingerprint impressions can be classified or grouped into ridge patterns -- loops, whorls, and arches -- arrestees who use aliases can be physically identified. Through centralized fingerprint repositories comprised of millions of fingerprint cards, individual arrest histories can be maintained on habitual offenders. These fingerprint collections are also responsible for the apprehension, every year, of thousands of fugitives. For example, a suspect wanted in for murder in Seattle who is arrested for burglary in Tampa, after his prints are matched with the Seattle fingerprint card, can be held in Tampa for the authorities who have been looking for him.

Beyond the use of fingerprinting to maintain crime records and to catch fugitives, crime scene finger marks -- so-called latent fingerprints -- constitute one of the most common methods of linking suspects to the sites of their crimes. While latents can be made visible by various chemicals, iodine fuming, and laser technology, the most popular method of identifying and preserving fingerprints, particularly on hard surfaces, involves the use of fingerprint powder and special lifting tape.

Crime scene latents can now be fed into a massive computer -- the Automated Fingerprint Identification System (AFIS) -- and matched with a single rolled-on impression in the computer. Identifying unknown crime scene latents in this way is one of the few instances where forensic science can solve and prove the case. Perhaps the three most significant developments in the history of law enforcement and criminal investigation include fingerprint classification, AFIS, and the cutting edge science of DNA "fingerprinting."

In the past called forensic ballistics, this forensic science concerns itself with the comparison and identification of crime scene bullets and shell casing firing pin impressions with the marks on test-fired rounds in the crime lab. If the marks on the bullet made by the test gun barrel are identical to the striations (rifling scratches) on the crime scene bullet, or the firing pin impressions are the same, the crime scene weapon has been identified. The science is grounded on the principal that no two guns will leave the same marks on the ammunition. Bullet striations and firing pin impressions are unique as a person's fingerprints. Firearms identification also involves restoring filed off serial numbers, retracing projectile flights, identifying the various types of bullet wounds, and determining the range of close range shots through powder stain patterns on the target. Firearms identification experts apply the sciences of metallurgy, chemistry (gunshot residue analysis), microscopy, and ballistics. A knowledge of the gun smith trade is also useful. Like document examiners, forensic firearms experts are trained on-the-job in crime laboratories.

In order for a polygraph result to be accurate, the instrument must be in good working order; the examiner properly trained and experienced in question formulation and line chart interpretation; and the subject (examinee) a willing participant in the process. Not everyone is suited for polygraph testing. People who are ill, on drugs or alcohol, extremely obese, retarded, or mentally unbalanced should not be tested. The more serious the crime, the more reliable the results. It is important that the examiner be familiar with the details of the crime in question, otherwise he or she may not ask the most appropriate questions. The polygraph instrument measures and records the examinee's involuntary, physiological (bodily) responses to a set of ten yes or no questions. The examinee will know in advance what questions will be asked. Based upon changes in the examinee's blood pressure, heart rate, breathing patterns, and galvanic skin response, the examiner will draw conclusions whether, in response to the payload question - did you kill your uncle? - the subject is lying or telling the truth. Polygraph examiners are not recognized by the criminal courts as expert witnesses, therefore polygraph results are not admissible as evidence in criminal cases. A federal law passed in 1988 prohibits the use of the polygraph technique as a private sector pre-employment screening device. Most law enforcement agencies at all levels of government do test job candidates. It is a widely used investigative tool, and there are about a dozen polygraph schools in the United States.

Also referred to as questioned document examination, this branch of forensic science includes the identification of handwriting paper, ink, typewriting, and writing instruments. Ninety percent of a document examiner's work has to do with the comparison of known handwriting samples with the questioned writing - a bank robbery note, a ransom document, the address on a mail bomb, a threatening letter, and signatures in wills, insurance policies and contracts that might have been forged. Examiners utilize chemistry, specialized photography, and microscopy in their work. A few specialize in the restoration of charred and burned documents. As forensic experts, they are often called to court as expert witnesses in civil and criminal cases. There are no schools for this kind of work, all education and training comes on-the-job in federal, state, county or big city crime laboratories.