Encyclopedia of Psychology and Law

later, the witnesses participate in a face-to-face inter-

view, which is either the CI or a control interview. The

control is either a “standard” police interview or a

“structured interview,” which incorporates generally

accepted principles of interviewing minus those tech-

niques unique to the CI. The interviews are usually tape-

recorded, transcribed, and then scored for the number of

correct statements and incorrect statements. Across

these studies, the CI has typically elicited between 25%

and 100% more correct statements than standard or

structured interviews. This effect is extremely reliable:

Of the 55 experiments examined in a recent meta-

analysis, 53 experiments found that the CI elicited more

information than did the comparison interview (median

increase =34%). Equally important, accuracy was as

high or slightly higher in the CI interviews (accuracy

rate =.85) than in the comparison interviews (.82).

All the above studies were conducted in the labora-

tory, with nonthreatening events. Two other studies

have examined the CI with victims and witnesses of

real-world crimes. In both of these studies, one con-

ducted in Miami and one in London, some experi-

enced police detectives received training to use the CI

and other experienced detectives did not receive such

training. In both studies, the CI-trained police investi-

gators elicited considerably more information than did

the untrained investigators (approximately 50% more

in the U.S. study).

Although most of the empirical testing has been

conducted on normal, healthy adults, several studies

have examined the CI’s effectiveness on unusual pop-

ulations, including young children, the elderly, and

those with cognitive deficits. Naturally, healthy col-

lege students remembered more than these other pop-

ulations. However, the CI was equally effective with

all the groups, enhancing their recollections by

approximately the same amount. Some have ques-

tioned the advisability of using the CI with very

young children, under the age of 5 years.

Most empirical studies have tested witness recall

within a few hours or a few days of the critical event.

Some studies, however, have shown the CI to enhance

witness recall after several months, and one study

even showed a very large benefit after 35 years.

The CI has been demonstrated to work effectively

in a variety of investigative interviews in addition to

criminal investigation—for example, accident or

public health investigation. It has not, however, been

effective in identification tasks: Witnesses given a

CI prior to an identification test (e.g., lineup) were

no more accurate than witnesses given a control

interview.

Practical Issues

Given the success of the CI in laboratory and field

experiments, how does it fare in real-world investiga-

tions? The CI has been used successfully to solve

several cases, including a kidnapping, a politically

motivated bombing, and child molestation. Recently, an

investigator from the U.S. Bureau of Alcohol, Tobacco,

and Firearms reported conducting a CI with a 38-year-

old woman who had witnessed a homicide as a 5-year

old child. The interview elicited scores of recollections,

many of which were corroborated by police records

established at the time of the crime (e.g., the location of

objects and furniture at the crime scene).

Offsetting these successes, the British police

reported that the complete CI was sometimes difficult

to implement. They noted difficulty in communicating

to witnesses some of the CI’s mnemonic instructions.

Other police officers have reported that using the

complete CI frequently requires more time than is

available, and so they often use only some of the com-

ponent techniques.

Other Investigative Tasks

Although the CI was developed initially to facilitate

witness memory of a crime, the technique has been

shown to be effective in other interview settings. Two

such applications of the CI are interviewing suspects

and debriefing jurors after deliberation.

Detecting Deception.Some research shows that the CI

facilitates detecting whether a suspect’s testimony is

truthful or deceptive. Two CI components that enhance

detecting deception are asking open-ended informa-

tion-gathering questions (vs. accusatory questions) and

encouraging suspects to take an active role. These

techniques generate longer responses from suspects,

thereby permitting more opportunities to identify ver-

bal and nonverbal cues to deception, and also allow

interviewers to detect the different response strategies

used by truth tellers and liars. In addition, asking sus-

pects to describe events in different sequential orders

(notably, reverse order) is particularly difficult for liars.

Debriefing Jurors.Reconstructing a jury deliberation

session after a trial should assist attorneys to evaluate

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