Solving a Murder Case by Asking Critical Questions: An Approach to Fact-Finding in Terms of Argumentation and Story Schemes

We use the term “fact” in its juridical sense, that is, descriptions of states or events the truth of which is currently unknown and has to be proven (cf. facta probanda or facts in issue, Anderson et al. 2005). With “evidence” we mean the evidential data, the primary sources of evidence the existence of which cannot be sensibly denied (e.g. witness statements made in court, forensic expert reports handed to the jury). Evidence and facts should not be confused: the existence of the evidential data does not guarantee the truth of the fact evidenced. For example, that there is a testimony by a witness who saw the suspect jump into a car does not guarantee that the suspect jumped into a car (the witness might lie or he might confuse the suspect with someone else).

The concept of argumentation schemes was introduced by Perelman and Olbrechts-Tyteca (1971). See also Garssen (2001), van Eemeren and Grootendorst (1992), Kienpointner (1992) and Walton et al. (2008).

The idea of general patterns of (types of) events that underlie stories stems from literature theory (e.g. Propp 1968) and has found applications in Cognitive Psychology and AI (Rumelhart 1975; Schank and Abelson 1977; Schank 1986). We have previously addressed the role of story schemes in the process of proof (Bex 2009; Bex and Verheij 2010; Bex 2011).

We started our analysis of this case in (Bex and Verheij 2009; Bex and Verheij 2011a), of which the present paper is an extension.

In the Netherlands the judges are required to provide a written verdict in which their considerations are summarized. Many of these verdicts are available to the public on http://​www.​rechtspraak.​nl. The verdicts in the Nadia van der V. case are available (in Dutch): LJN AO3150 (court of Utrecht) and LJN AT5190 (court of appeal Arnhem).

This approach has its roots in Wigmore’s (1931) evidence charts and has been further developed by “New Evidence Theorists” such as Anderson et al. (2005). Similar argument structures have been discussed by, among others, Freeman (1991), Reed et al. (2007) and Verheij (2005b). Bex et al. (2003) have further discussed the link between Wigmore’s graphs and such argument structures.

This explanatory story-based approach, the main proponents of which are Wagenaar et al. (1993) and Pardo and Allen (2007), is based on work from cognitive and legal psychology (Bennett and Feldman 1981; Pennington and Hastie 1993).

Argumentative analyses of the anchored narratives theory by Wagenaar, Crombag and Van Koppen have been given by Verheij (2000), Bex et al. (2006) and Verheij and Bex (2009).

Anderson et al.’s work, for example, is firmly based on what is called the Rationalist Tradition (Anderson et al. 2005, pp. 78–86), which argues that it is necessary to rationally reason with the evidence in order to establish whether or not our belief in the facts is justified. Conversely, Bennett and Feldman’s (1981) and Pennington and Hastie’s (1993) work was also meant as a descriptive theory of how people reason with masses of evidence in legal cases.

The rhetorical role of both arguments and stories, while interesting, has not been explored in the work on the hybrid theory.

See van Eemeren (1994) for a concise introduction to this view.

Often, new explananda appear during the investigation or treatment of a case. For example, once a possible suspect has been found a new explanandum could be “why was this man acting suspiciously near the crime scene?”

Josephson (2002) discusses abductive reasoning in the context of reasoning with narratives and criminal evidence. Walton (2001) provides a more general account, contrasting abductive reasoning with presumptive and plausible reasoning.

Often, c explains e because c is a cause of e and in our other work we mostly model explanation using causal links. However, in order to sidestep the often difficult and subtle discussions about causality, here we simply talk about explanatory relations. This also allows, for example, teleological or intentional explanations (see also Bex et al. 2009; and Bex 2011, pp. 24–31).

Pennington and Hastie (1993) say that a story is coherent if it is consistent and it follows a general motive—goal—action—consequence sequence (see Sect. 3.2) and any individual causal links in the story are plausible. In Thagard (2004) coherence depends on the numerical strength of the explanatory relations between events in the story, which is in turn determined by formal coherence principles.

See e.g. Walton et al. (2008, Chap. 5).

As is argued by Schank and Abelson (1977) and Schank (1986), the knowledge that is used when thinking about patterns of action often does not have the form of individual causal or explanatory rules but is more naturally thought of as a collection of coherent and generalized events or event types, see Sect. 3.2.

Experiments by Pennington and Hastie (1993) have shown that stories that explain the facts are closest to how legal decision makers actually think about a case and Wagenaar et al. (1993) hence argue that stories are the only viable way to argue with complex masses of evidence.

See Bex and Walton (2010), Pardo and Allen (2007), who have argued that reasoning in trials involves comparing stories about the facts.

Twining (1999) and Anderson et al. (2005) argue that stories are “dangerous” because they can, for instance, be based on false generalizations, and Wagenaar et al. (1993) argue that we should be careful not to let a “good” story push away a “true” story.

This observation was already made by Pennington and Hastie (1993) and Wagenaar et al. (1993), who say that a story must explain the evidence and that it must be anchored in safe commonsense knowledge.

See (Bex and Verheij 2011b) for a further discussion on how sets of facts can be used as reasons for legal conclusions.

This is the case in, for example, Pennington and Hastie’s (1993), Josephson’s (2002) and Thagard’s (2004) approaches.

In Walton's treatment, argumentation schemes do not only occur as generalized rules of inference, but also as (generalizable) small derivations or pieces of dialogue (Verheij 2003). Cf. also Prakken (2010) who argues that some argumentation schemes are compressions of more complex types of defeasible reasoning and Verheij (2009), who shows how argumentation schemes have been incorporated into more formal models of argumentation.

See Hitchcock (2010) for an exposition of how logicians or epistemologists might go about constructing (new) argumentation schemes.

In Bex and Verheij (2011b), we further explain the link between the factual and the legal aspects of a case.

There is theoretical discussion about the nature and existence of direct evidence, see for instance Anderson et al. (2005), pp. 62–63. For our purposes, it suffices to note that we consider an event to be directly supported when there is a direct, argumentative (evidential) chain of reasoning from evidence to the event.

Pennington and Hastie (1993) have shown that the chronological ordering is more convincing than an arbitrary ordering.

Freeman (2006) has provided a classification of types of warrants based on epistemic considerations. He distinguishes a priori, empirical, institutional and evaluative warrants.

The tests raised controversy in another well-publicised Dutch case, namely the Deventer Moordzaak.

This second example is based on an actual Dutch case, aptly named the “Ballpoint-case” (Feteris 1999).

The exact role and nature of the weighing of reasons goes beyond the goals of this paper. In our perspective on the weighing of reasons, the issue whether certain given pros outweigh given cons is itself open for argumentation. For instance, in the law, precedents can sometimes be used to argue how certain reasons must be weighed. See also Wellman (1971), Naess (1978), Govier (1999), Feteris (2008), Hage (1996, 1997), Verheij (1996). The debate on the weighing of reasons has recently been revived by the Symposium on Conductive Arguments, organized at University of Windsor in 2010 (about which a special issue of the journal Informal Logic is in preparation).