Abstract
The field of forensic science has transformed the field of criminal investigations. The value of forensic science is that it yields reliable and accurate evidence. Fingerprint analysis and DNA evidence are methods for accurately identifying a particular individual made possible through forensic science and testing. In addition to the advent of forensic science, national crime databases such as IAFIS enable investigators and law enforcement officials to search through millions of fingerprints and DNA profiles for a potential suspect. The value of fingerprints and DNA as evidence is that it is not subject to manipulation or subjective interpretation. Other forms of evidence, such as eyewitness testimony, have yielded many erroneous convictions based on faulty or mistaken testimony. In the case of Sacco and Vanzetti, eyewitness identification was the primary evidence used to convict these defendants. This case occurred well before modern forensic science, and it is doubtful to this day whether the eyewitness testimony relied upon was truthful or mistaken.
Introduction
Many crimes are made possible to solve through the use of forensic science. The advent of advanced scientific testing and technology has equipped investigators with the tools and resources to solve many difficult crimes. Today, forensic science serves many different purposes. First, forensic evidence is one of the most reliable forms of evidence in a criminal trial. Unlike witnesses, forensic evidence, such as DNA, does not lie. Thus, the presence or absence of DNA in a criminal investigation can often make or break the case. A second purpose of forensic evidence is its ability to exonerate innocent persons. To date, 336 innocent persons have been exonerated through DNA testing (Innocence Project). Third, forensic science has transformed the methods of criminal investigations. With the many different forensic tests available today, even the most minute sample size of evidence could be of high value.
Fingerprints
One of the most significant forensic science breakthroughs in the criminal justice system is the proliferation of fingerprint analysis. Ancient China marks the beginning of fingerprints as a means of identification (Owen, 2000, p. 160). The Chinese used fingerprints to endorse legal contracts of the parties to be bound by the instrument (Owen, 2000, p. 160). What sets fingerprints apart from other types of evidence is their uniqueness. Because each fingerprint contains unique and distinct characteristics of the individual, fingerprints are of high value to investigators (Kaushal and Kaushal, 2011, p. 1). The probability of any two fingerprints being identical is infinitesimally small. Francis Galton estimated there is a 1 in 64 million chance of finding two identical fingerprints (Kaushal and Kaushal, 2011, p. 1). Because fingerprints are so unique to the individual and no two are exactly alike, fingerprints are an accurate and reliable way to identify a particular individual.
Another feature of fingerprints that gives them such a high evidentiary value is that they remain the same throughout a person’s lifetime. Unlike facial features or body stature, the ridge patterns on an individual’s fingerprints are unchanged from the time of birth to death (Kaushal and Kaushal, 2011, p. 1). Fingerprints are categorized into three different groups based on ridge patterns. The three different fingerprint ridge patterns are loops, whorls, and arches (Kaushal and Kaushal, 2011, p. 1). The most common type of pattern are loops, comprising of 60-65 percent of the population (Kaushal and Kaushal, 2011, p. 1). About 30-35 percent of the population is comprised of whorls (Kaushal and Kaushal, 2011, p. 1). The rarest ridge pattern is arches, making up only 5 percent of the population (Kaushal and Kaushal, 2011, p. 1).
Forensic science and technology has paved the way for very advanced computer programs that match various ridge marks and characteristics between different prints. The Federal Bureau of Investigation keeps a national database of fingerprints on file in a program called Integrated Automated Fingerprint identification System (IAFIS) (Integrated Automated Fingerprint identification System). The IAFIS system currently has over 34 million prints and is available for law enforcement officials at the federal, state, and local levels to search through and locate potential known matches (Integrated Automated Fingerprint identification System). IAFIS is extremely useful for improving the coordination between various law enforcement agencies and departments. Before fingerprint analysis and IAFIS, it would have been impossible for police in one state to match unknown prints to a known suspect in another state. But with IAFIS technology, coordinate branches of law enforcement now have the ability to share important investigative information with each other much more efficiently.
Sacco and Vanzetti
One of the most controversial and unrealizable forms of evidence is eyewitness testimony. A striking truth about eyewitness testimony is that 80 percent of persons exonerated were found guilty because of were erroneous eyewitness identification (Duke, 2007, p. 2). In contrast with physical evidence or DNA evidence, witnesses can easily lie or manipulate the truth. Even if a witness does not intentionally lie during testimony, the human memory is extremely unreliable. There have been a number of questionable criminal cases where the primary evidence relied upon was eyewitness testimony (Goss, 1999, p. 307). A famous case illustrating the dangers of over-reliance on eyewitness testimony was the prosecution of Sacco and Vanzetti.
Sacco and Vanzetti were two Italian immigrants in the 1920s (Linder, 2001). Every Thursday, the morning train from Boston was carrying around $30,000 in payroll money for shoe factories ((Linder, 2001). The money was due to be received by a man named Neal. On April 15, 1920, Neal noticed a strange car parked in the vicinity of his office that he did not recognize (Linder, 2001). The mysterious touring car was a dark blue color (Linder, 2001). The windows of the car were closed, but Neal saw a haggard-looking man sitting hunched over in the front of the car (Linder, 2001). After Neal took the money and left it in one of the offices, nearby residents would report spotting a blue touring car cruising through the streets (Linder, 2001). These residents stated that they saw five men in the car who were dark and “probably Italian” (Linder, 2001).
Around 3:00 pm that afternoon, the paymaster and his guard retrieved the $30,00 contained in the payroll envelopes from the office where Neal dropped the money off that morning (Linder, 2001). The two men left the office and walked down the street with the money, intending to distribute the money to the employees (Linder, 2001). All of a sudden, shots were fired (Linder, 2001). A man in a felt cap pointed a gun at the guard and fired several shots, hitting the guard in the heart (Linder, 2001). In the meantime, a second gunman hit the paymaster (Linder, 2001). After the paymaster and the guard were shot, the two gunmen got into a blue touring car, escaping with the money (Linder, 2001). The incident was witnessed by dozens of eyewitnesses (Linder, 2001).
Sacco and Vanzetti were arrested for the murders. Because there was no evidence definitively linking these two defendants to the crime, the prosecution built its case against Saco and Vanzetti mostly based on eyewitness testimony and other circumstantial evidence (Linder, 2001). Several witnesses identified both Sacco and Vanzetti as being at the scene of the crime (Linder, 2001). The defense called eyewitnesses that refuted the prosecution and these eyewitnesses placed Sacco and Vanzetti elsewhere at the time of the incident (Linder, 2001). Both defendants, however, were ultimately convicted and sentenced to death (Linder, 2001). Whether thee defendants were actually guilty is a subject of continued debate among scholars.
Conclusion
The most accurate type of evidence is certainly some sort of forensic or DNA evidence. It is very difficult to dispute the reliability of a fingerprint or DNA evidence. Other forms of evidence, however, are notoriously unreliable. Such is the case of eyewitness testimony, which has resulted in numerous wrongful convictions over the years. The criminal trial of Sacco and Vanzetti demonstrate firsthand the unreliability of eyewitness testimony. Although eyewitness testimony may prove helpful in certain cases, it should not be the sole form of evidence used to convict a defendant. As forensic science and DNA provide have led to fewer numbers of mistaken convictions, unreliable evidence like eyewitness testimony should be used less and less.
References
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http://www.innocenceproject.org/free-innocent/exonerating-the-innocent
Integrated Automated Fingerprint identification System (n.d). Federal Bureau of
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