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IDENTIFICATIONTESTS,

BESTPRACTICES IN

Perhaps the ultimate form of eyewitness evidence is

the identification of a suspect from a live or photo

lineup, as opposed to more general information pro-

vided by a witness, such as a verbal description of an

event. Best-practice recommendations in this area are

based on a combination of some good procedures used

by law enforcement for decades, sound logic and prob-

ability theory, basic psychological principles, and ded-

icated psychology–law research. The primary goal of a

good identification procedure is to let the witness’s

memory be the basis of his or her decision, rather than

any implicit or explicit influences that derive from

either the procedure used or the nature of the lineup

itself. And, of course, the desired outcome of a good

procedure is to secure either an accurate identification

of a guilty suspect or a “Don’t know” or “Not there”

response if the actual offender is not in the lineup.

There are at least four techniques for obtaining an

identification from an eyewitness, and most of the best-

practice procedural recommendations apply in all of

them (as opposed to filler-selection issues, for example,

which don’t apply for at least one of the techniques).

The two techniques that have received the most atten-

tion by researchers and the legal community, and are

the primary focus of this entry, are live lineups (also

known as identification parades in the United Kingdom

and some other countries) and photo lineups (also

known as photo arrays or photo spreads and sometimes

called a “6-pack” in the United States, in reference to

the most common number of photos used). The other

two procedures are the field identification procedure

(often called a “showup”), in which just one individual

is shown to a witness, usually soon after an event has

occurred and within close proximity to the scene, and

the in situ procedure, in which a witness is asked to

view a group of individuals in a relatively informal set-

ting, such as the lobby area of a police station or a pub-

lic location that a suspect is known to frequent, such as

a bar or a place of employment.

The showup is thought by most eyewitness

researchers,and some courts, to be “inherently sug-

gestive,” and few researchers would recommend it as

a best-practice technique. The two most obvious

potential advantages of a showup are that a potentially

dangerous person could be detained on the basis of a

positive identification, often with the aim of protect-

ing a person who might be revictimized otherwise,

and that an innocent suspect could be quickly exoner-

ated. The showup procedure is included as a legiti-

mate option in the U.S. National Institute of Justice

(NIJ) document “Eyewitness Evidence: A Guide for

Law Enforcement,” published in 1999, and the

Wisconsin Department of Justice’s “Model Policy and

Procedure for Eyewitness Identification,” released in

2005. Despite the situations in which the potential
      advantages of a showup might outweigh the otherwise
      prudent decision to conduct either a live or a photo
      lineup with nonsuspect fillers, the best practice-rec-
      ommendation is to think of a lineup as the default pro-
      cedure. It is not unreasonable, for example, to expect
      that law enforcement can use current and near-future
      technology to construct an electronic photo lineup at
      a crime scene using a digital image of a suspect
      who was found in the vicinity and benefit from the

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