Expert Witness

Early Experts

Courts used expert, but nonscientific, knowledge as early as the fourteenth century, when juries composed of craftsmen or tradesmen often heard cases within their specialties. In other cases, jurors were scholars, engineers, and physicians. Ideas from science affected legal practice as early as the 1692 witch trials in Salem, Massachusetts. At least nineteen people were executed and others incarcerated and ruined financially before questions about the reliability of the evidence ended the trials. Thus, ideas from science heightened concerns about false identifications and executions. In 1782, a civil engineer became the first known expert to testify from the witness stand.

Early Physical Science

Most early expert witnesses used techniques that identified types of physical evidence. These techniques helped determine whether a crime had been committed and guided the collection of evidence. This work is now known as forensic science. “Forensic science in its broadest definition is the application of science to law” (Saferstein 2001: 1).

Matthieu Orfila (1787–1853) published the first scientific work on the detection and effects of poisons. Alphonse Bertillon (1853–1914) created the first system of personal identification; although fingerprints replaced his body measures, he is known as the father of criminal identification. In 1892, Francis Galton (1822–1911) published Fingerprints, a book that is still used today. Leone Lattes (1887–1954) built on Karl Landsteiner's 1901 discovery of the four blood types: A, B, AB, and O. In 1915, Lattes developed an investigative procedure using dried bloodstains. Calvin Goddard's (1891–1955) comparison microscope improved the ability to compare crime scene bullets with ones fired from suspects' guns. Albert S. Osborn's (1858–1946) book Questioned Documents, published in 1910, still guides document examinations. In 1893, Hans Gross (1847–1915) described how information from several scientific disciplines can apply to criminal investigations.

Eventually, forensic crime labs became centers of training and technical assistance for police. The first U.S. lab was established in 1923 by August Vollmer in Los Angeles, California. The best-known lab was created in 1932 by the Federal Bureau of Investigation (FBI). Most persons performing lab tests or testifying worked for the prosecution and were law enforcement officers or had law enforcement experience. This link still exists: “About 80 percent of forensic scientists in North America are affiliated with police or prosecution agencies” (Kelly and Wearne 1998: 15).

The first important case relating to the qualifications of expert witnesses was Frye v. United States (1923). The defendant, Alphonso Frye, confessed to committing murder, but he later withdrew his confession, saying that he had passed a deception test that measured blood pressure. A federal court ruled that [Page 660]this lie detector did not have “general acceptance” within the scientific community. This judgment became known as the Frye Rule: without general acceptance, techniques and the evidence they produced were excluded from court. For more than fifty years, this rule applied in most federal and state courts.

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