Towards a Model of (Insider) Witness Assessments in International Crime Cases: An Experimental Vignette Study

• Published date: 01 March 2024
• DOI: http://doi.org/10.1177/10575677221126903
• Author: Gabrielė Chlevickaitė
• Date: 01 March 2024

Towards a Model of (Insider)

Witness Assessments in

International Crime Cases: An

Experimental Vignette Study

Gabriele

̇Chlevickaite

̇

1

Abstract

Trials of international crimes frequently rely on a complex type of witnesses: insiders or accom-

plices. While harnessing essential knowledge, insiders pose serious challenges to the decision-mak-

ers assessing their credibility. Prior research suggests that judges dismiss a sizeableproportion of

insider testimony during trials of international crimes.While some reasons might lie with the wit-

nesses, a closer look at the professional practices is warranted. This study aimed to examine the

process of insider witness statement assessments by international criminal justice professionals

and to analyze how they resolve the tension between the concerns about witness truthfulness

and the quality of the testimony. One hundred sixty practitioners took part in an experimental

vignette survey. Results of qualitative analyses demonstrate that the assessments of the witness

and the statement contents are interrelated: across all experimental conditions, respondents

drew inferences about the quality of the testimony based on their assessment of the witness and

vice versa. Furthermore, the same indicators were given various, at times contradictory, meanings,

highlighting individual differences in professional practice and the noise in decision-making.

Keywords

Witness evidence, experiment, international criminal justice, ICC, credibility

Introduction

Despite the increasing use of digital, forensic, and documentary sources of proof (Dubberley et al.,

2019; Freeman, 2018), witness testimony is still frequently used in (international) criminal proceed-

ings. Witness evidence, however, continues to challenge fact-f‌inding. On the one hand, questions are

raised regarding witnesses’capabilities to provide accurate accounts of the events they had observed

or experienced (Paulo et al., 2019; Wade et al., 2018). On the other, there is an increasing examina-

tion of the fact-f‌inders’abilities to reliably determine the witness’s honesty and accuracy

1

Vrije Universiteit/Fellow Netherlands Centre for the Study of Crime and Law Enforcement, Amsterdam, the Netherlands

Corresponding Author:

Gabriele

̇Chlevickaite

̇, Assistant Professor, Vrije Universiteit/Fellow Netherlands Centre for the Study of Crime and Law

Enforcement, De Boelelaan 1077, 1081 HV, Amsterdam, the Netherlands.

Email: g.chlevickaite@vu.nl

Original Article

International Criminal Justice Review

2024, Vol. 34(1) 43-68

© 2022 Georgia State University

Article reuse guidelines:

sagepub.com/journals-permissions

DOI: 10.1177/10575677221126903

journals.sagepub.com/home/icj

(McDermott, 2017; Sagana, 2018; Simon, 2012; Wistrich & Rachlinski, 2017). This determination is

further complicated where fact-f‌inders rely on accomplices or otherwise involved witnesses (Cryer,

2014; Nicolson & Auchie, 2017), commonly referred to as “insiders”in international crime cases

(Kelsall, 2009; Whiting, 2009).

Assessing the accuracy, completeness, and objectivity of evidence provided by insider witnesses

is a formidable task. Insiders are highly valuable. They harness privileged, unique information which

might be crucial to establishing individual criminal responsibility of higher-ranking accused, com-

monplace at the International Criminal Courts and Tribunals (ICCTs) (Del Ponte, 2006; Fry,

2014; Wald, 2002). In this sense, insiders appear as quasi-experts on the organization in question,

often providing evidence on the military and political structures, de facto functioning of the

groups, and actions of the accused (Chlevickaitėet al., 2020; Wald, 2002). On the other hand,

insiders present specif‌ic concerns regarding their objectivity and trustworthiness. The motivation

of insider witnesses to testify, especially in the absence of plea agreements (Cook, 2005; Harmon,

2009), is a crucial issue in determining whether a witness can be expected to provide a complete

and truthful account (Chlevickaitėet al., 2020; Stepakoff et al., 2014). Unlike victim-witnesses,

insiders might, for instance, have been involved in the commission of crimes, have personal rela-

tionships with other members of the criminal organization, including the accused, or have related

security concerns that might inf‌luence the extent to which they are willing or able to tell the whole

truth (Cryer, 2014; Stover, 2005). Hence, the decision-makers are walking a tightrope between

their concerns about the honesty of the witness and the signif‌icance of the evidence they might

provide.

It is diff‌icult, if not impossible, to estimate whether practitioners’decisions about witness evi-

dence are accurate, as no ground truth is readily available. Nevertheless, prior research has shown

that judges f‌ind issues with up to 50% of insider witness evidence at ICCTs, to the extent that

their probative value is profoundly compromised (Chlevickaitėet al., 2021). The implicationsof

such a magnitude of loss of evidence at trial are considerable. Not only does it impact case outcomes,

but it also means that many insider witnesses testify unnecessarily, without contributing to fact-

f‌inding, which is both expensive to the ICCTs and potentially life-altering to the witnesses.

1

Multiple explanations for this state of affairs are possible, both external: among other things,inves-

tigative challenges in uncooperative environments (Çakmak, 2017), multilingual and cross-cultural

nature of the assessments (Kelsall, 2009; Nistor et al., 2020), time lapses (Bradf‌ield, 2019), trauma

(Smeulers & Grunfeld, 2011); and internal: for example, the mismatch between investigative, pros-

ecutorial, and judicial witness assessment practices; inaccurate, inconsistent, or biased decision-

making. While external factors are mainly out of the hands of ICCT practitioners, internal processes,

and standards of witness evidence assessments can be studied and evaluated.

Assessment of Source: (Insider) Witness Credibility

Credibility assessments in criminal justice contexts consist of evaluating a witness’s objectivity

(or honesty) and competence (Delisle, 1978; Schum & Morris, 2007; Sluiter et al., 2013). Similar

to domestic settings (Brodsky et al., 2010; Cohen, 2013; Kane, 2007), at the ICCTs, objectivity is

assessed in reference to the witness’s character and background information on prior relationships,

membership in particular groups, identity (ethnic, national, other), the harm suffered, and incentives

to testify (Chlevickaitėet al., 2020). Furthermore, though largely discouraged based on current sci-

entif‌ic knowledge (Snook et al., 2017; Vrij et al., 2019), objectivity assessments continue to take into

account the witness’s behavior on the stand as an indicator of truthfulness as well (Chlevickaitėet al.,

2021). While, arguably, nonverbal communication might serve other informative purposes during

fact-f‌inding (Denault et al., 2019), the risks of inappropriate assessments in cross-cultural settings

are substantial (Johannesson, 2012; Vrij et al., 2011).

44 International Criminal Justice Review 34(1)