Professional forensic science organizations promulgate codes of ethics for their members. An example is the code of ethics of the American Society of Crime Lab Directors (ASCLD), developed in 2004, which states in part, ". . .as members of the American Society of Crime Laboratory Directors, we will strive to foster an atmosphere within our laboratories which will actively encourage our employees to understand and follow ethical practices. Further, we shall endeavor to discharge our responsibilities toward the public, our employers, our employees and the profession of forensic science in accordance with the ASCLD Guidelines for Forensic Laboratory Management Practices."
Any code of ethics articulates high ideals for its profession, but wide gaps can emerge between ideals and the reality of professional practice as it is carried out by fallible, and sometimes dishonest, human beings. Forensic science has not proven itself immune from these gaps.
For example, consider the performance of crime labs. The federal Clinical Laboratory Improvement Act established minimum standards for clinical laboratories in 1967, and the law was toughened in 1988. Both times, though, forensic laboratories remained exempt from the law, largely because it was assumed that such labs did not need such regulation. Under public pressure, though, the ASCLD in 1981 created an accreditation arm for the nation's some 400 crime labs. Fifteen years later, just 138 of those labs had earned accreditation, and the ASCLD refuses to release information about any labs that have applied for but failed to gain accreditation.
Meanwhile, studies have documented alarming levels of error in the nation's crime labs, leading molecular biologist Eric Lander to note: "Clinical laboratories must meet higher standards to be allowed to diagnose strep throat than forensic laboratories must meet to put a defendant on death row." While many of these errors result from simple human error, many represent a pattern of ethical lapses. In 1994, USA Today documented 85 cases over a 20–year period in which prosecutors had deliberately falsified evidence ; during the same period at least 48 people were freed from death row when it was discovered that they were convicted on the basis of false evidence or that the prosecution had deliberately withheld potentially exculpatory forensic evidence.
Further, anecdotal cases of ethical lapses abound. A police forensic expert hired by the West Virginia State Police crime lab and later by the county medical examiner's office in San Antonio testified for 15 years, often in capital cases, about lab tests he had never run. A West Texas medical examiner faked over 100 autopsies and falsified blood and toxicology reports. An examiner in the FBI crime lab'sserology unit, who repeated lied under oath about his credentials, was found to have faked lab reports, including reports of blood analyses he never conducted, and to have issued reports confirming the guilt of suspects when he had ignored or distorted actual test results.
These ethical lapses could be dismissed as aberrations, but doing so does not erase the central ethical concern that confronts forensic science each day, the inherent conflict between science and advocacy. Scientists are dispassionate observers, not advocates for one side or the other. As scientists, forensic examiners are ethically obligated by the profession to follow the evidence wherever it leads, without bending to pressure from judges, prosecutors, the police, or the public to find results that serve their purposes. Scientists follow documented and widely accepted protocols in carrying out their work rather than working from an oral tradition that prevents outsiders from examining and questioning their methods. Scientists must follow the scientific method, which demands peer review so that other scientists can expose flaws in theories and procedures. At the heart of the scientific method is the criterion of "falsifiability." This criterion requires that for a theory to prove that X caused Y (e.g., that the defendant's gun fired the bullet), it has to state not only what is true (the markings on the bullet prove that it came from the defendant's gun), but also imply that other things could not be true (the markings could not have come from another gun). If those "other things" do in fact turn out to be true or could be true, the original theory has to be abandoned. All of this at the heart of the scientific method.
Forensic science is sometimes accused of being an arm of the prosecution—whose function is advocacy, not science—in large part because most forensic investigators are not independent experts. Estimates are that 80% of forensic examiners work in police laboratories, and most of the 80% and their superiors are law enforcement officers. As James Starrs, a law and forensic science professor at George Washington University, has noted, "They analyze material submitted, on all but rare occasions, solely by the prosecution. They testify almost exclusively on behalf of the prosecution. . . As a result, their impartiality is replaced by a viewpoint colored brightly with prosecutorial bias."
Rule 16 of the Federal Rules of Criminal Procedure states that all "results and reports" of forensic examiners are "discoverable" to the defense, meaning that the prosecution has to provide them to defense attorneys on demand so that they can examine the reports rather than having to accept the testimony of forensic examiners at face value. Some members of the forensic science and criminal justice communities consider Rule 16 problematic in two main areas. First, not all "results and reports" are written, or if they are, they are often brief and conclusory, sometimes deliberately so. Nothing requires forensic examiners to document their methods and procedures, so the defense sometimes has no meaningful way to examine "results and reports" that do not exist anywhere on paper. Some forensic labs have resisted inquiries into their methods and procedures; by committing as little as possible to paper they protect themselves from potentially damaging questions.
Another concern with Rule 16 is that it does not mention such items as notes, calculations, graphs, computer printouts, and other records made during testing. The courts have consistently ruled that these items are not discoverable because they do not represent the end product of forensic examination, "results and reports." During the 1983 trial of Wayne Williams, the Atlanta man accused of killing some 30 young African Americans, a hair and fiber expert testified for 11 days from bench notes, which the court ruled were not discoverable by the defense. Another expert testified about graphs produced during comparison of fibers from Williams's bedroom carpet and fibers found on the victims' clothing, but again the court ruled that those graphs were not discoverable. Further, defendants have no automatic legal right to test or retest evidence themselves, and labs have no legal duty to preserve records, including reports, bench notes, printouts, and the like, nor are they required to preserve physical evidence for later retesting.
In 1971, law professor James Starrs made proposals to solve these ethical problems at the institutional level. Among other things, he called for "full and complete disclosure of the entire case in a comprehensive and well-documented report," a requirement that forensic scientists "testify to the procedures undertaken and the results disclosed only when opinions can be stated in terms of reasonable scientific certainty," and a requirement that "a forensic scientist for the prosecution should permit the defense to interview him/her before the trial" without the need for the prosecutor's approval. In the years that followed, some of these proposals have been incorporated into forensic codes of ethics.
see also American Academy of Forensic Sciences; Forensic science.