through the trouble of arranging such a procedure. So witnesses often tell themselves the
culprit has to be there and feel pressured to identify somebody.
Much of the psychological research into eyewitness identifications suggests that officials
should use the may-or-may-not-be present instruction—the person administering the
procedure tells a witness before they view the lineup that the suspect may or may not be
present. The research shows that if this instruction is not given, misidentifications are more
likely than if it is given. Administrators can bias the lineup identification even more by
telling a witness that police have already found the perpetrator, that police know who the
perpetrator is, or that police have plenty of evidence against the perpetrator.
Administrators can also give witnesses other verbal and nonverbal cues that may not be
intentional or even done consciously.
Psychological Research and Eyewitness Identification
CRPR.SAMA.18.09.04 – Understand that empirical research has demonstrated that factors
such as lineup composition, neutrality of lineup administrators, pre-lineup instructions, and
the way the lineup is presented can be suggestive and affect the accuracy of identification.
62. Identify and explain the shortcomings of forensic evidence. Provide examples of how these shortcomings might apply
to criminal cases.
In his interrogation of flawed forensic evidence, Professor Roger Koppl (2007, 3–5), an
economist associated with the libertarian Reason Foundation, lists eight features of current
forensic science that reduce the quality of forensic practitioners’ work: monopoly,
dependence bias, poor quality control, information sharing, no division of labor between
forensic analysis and interpretation, lack of forensic counsel, lack of competition among
forensic counselors, and public ownership. Examples of application to criminal cases will
vary.
Forensic Science and Identification Evidence
CRPR.SAMA.18.09.06 – Know that DNA technology has prompted the reevaluation of many
past convictions and led not only to exonerations of the innocent, but also further proof
against the guilty. Understand that forensic science can provide compelling evidence of guilt
but also suffers serious shortcomings.