Chapter 8

Arguments, Stories and Evidence: Critical Questions for Fact-finding
Floris Bex
University of Dundee
Bart Verheij
University of Groningen
1. Introduction
In this paper, we look at critical questions for the process of reasoning about the facts
and the evidence in criminal cases.1 In the literature, essentially two approaches to thisreasoning can be can be distinguished: the argumentative and the narrative approach. In
the argumentative (or argument-based) approach, the facts should be supported byreasons based on evidence. Key questions for argumentative approaches include which
reasons can support which conclusions under which circumstances (the search forwarrants and argumentation schemes, cf. Toulmin 1958, Walton et al. 2008) and how tohandle conflicts of reasons and exceptions (the defeasibility of argumentation, cf. Loui
1995). The argumentative approach in legal fact-finding is based on Wigmore (1931),
whose hand-drawn evidence charts predate many later developments in legal theory(Anderson et al. 2005). The approach has been explored in the field of argumentation by
Walton (2002) and Bex et al. (2003), who propose and analyse numerous argumentation
schemes that can be used to reason from the evidence to the facts.
The second approach to the rational establishment of the facts involves
presenting these facts as narratives or stories – coherent descriptions of what might have
happened – that causally explain as much of the evidence in the case as possible. In acriminal case the narrative typically includes the events of the crime (e.g. the victim
being shot) information about the intentions of the criminal (e.g. vengeance) and theconsequences of the crime (e.g. a dead body). Key questions in a narrative approach
include how to establish the coherence and quality of stories (the search for plausibility
criteria), when to believe a story (the issue of justification of the belief in a story) andhow to choose between alternative stories (the issue of story comparison). The narrative
approach has been studied as a model of cognitive decision-making in the psychologyof law (Pennington and Hastie 1993, Wagenaar et al. 1993) and as a more analyticalmodel for inference to the best explanation in (legal) philosophy (Josephson 2002,
Thagard 2004, Pardo and Allen 2007). The narrative approach is less well represented
in the literature on argumentation. In this paper we will show that a strong analogy canbe drawn between reasoning patterns in argumentation, the familiar argumentation
schemes (Walton et al. 2008), and patterns in the narrative approach, which we callstory schemes (Bex 2009). These story schemes act as a background for particularinstantiated stories in the same way as argumentation schemes act as a background forparticular instantiated arguments. Furthermore, story schemes give rise to relevant
critical questions in the same way as argumentation schemes.
In our opinion, neither the purely argument-based nor the purely story-based
perspective can do justice to all relevant mechanisms as they are recognized and used by71

decision makers and investigators. Instead a hybrid argumentative-narrative approach,in which arguments and narratives can be used in conjunction as well asinterchangeably, is to be preferred (Bex et al. 2007, Bex et al. 2010, Bex 2011). In thispaper, we will review this hybrid approach in a semi-formal way (as opposed to theformal logical presentation of Bex et al. 2010), focusing on the types of schemes used inboth argumentative and narrative reasoning. Furthermore, we present the list of criticalquestions from (Bex and Verheij 2009),2 which point to typical sources of doubt in a
hybrid argumentative-narrative case in the same way as critical questions forargumentation schemes point to typical sources of doubt regarding a single inference.
These critical questions are then used to analyse the verdicts in the Nadia van der V.
Case.3 The case concerns Nadia, who has been killed in her home by several gunshots.
Her landlord, Pascal F., is regarded as the prime suspect. He has been seen fleeing town
in Nadia’s car and is not to be found until well into the next year. When Pascal is finallyapprehended, he is charged with murder and found guilty by the lower courts as well as
on appeal.
2. A hybrid argumentative-narrative theory
In this section, we will discuss the argumentative and narrative approaches before
proposing our hybrid combination. Additionally, the discussion below will also focus on
the use of various types of commonsense knowledge expressed as schemes. Reasoning
with evidence involves a large amount of commonsense knowledge about the world
around us, which allows us to assume or infer new information in a way that is as safe
as is needed in the context. In this paper, we show that in the argumentative approachcommonsense knowledge often takes the form of argumentation schemes (Walton et al.
2008), general patterns of argument that act as a background for particular instantiatedarguments, and that in the narrative approach such knowledge takes the form of generalscenarios that can be seen as story schemes (Bex 2009), standard general event-patterns
that act as a background for particular instantiated stories.
2.1. Argumentative Approach
In the argumentative approach, arguments are constructed by performing consecutive
reasoning steps, starting with one or more items of evidence and reasoning towards aconclusion, a fact at issue in the case. The reasoning steps in these arguments haveassociated generalizations that justify the inferences (cf. Toulmin’s warrants andWalton’s schemes). For example, the evidence ‘a witness testified that a man wholooked like Pascal was in the car’ and the generalization ‘witnesses usually speak thetruth’ allows us to infer that ‘a man who looked like Pascal was in the car’. This
intermediate conclusion can then be used to infer that it was indeed Pascal who was in
the car. Thus lines of reasoning can be combined to construct argument trees, which canbe rendered as diagrams (Freeman 1991; Reed et al. 2007). Take, for example, Figure 1.

72

The argument in Figure 1 uses typical generalizations, such as the above-mentioned
generalization about witnesses, to justify the inferences. These generalizations can berendered as argumentation schemes; for example, consider the scheme for Argumentfrom Witness Testimony (Walton et al. 2008, Bex et al. 2003):
Witness w is in a position to know whether a is true or not.
Witness w asserts that a is true (false).
Therefore, a may plausibly be taken to be true (false).
Now, Bob asserted that someone looking like Pascal was in Nadia’s and Bob was in aposition to know this, as he saw Nadia’s car. Similarly, the evidence that Pascal’s scent
was in the car is a sign for the fact that Pascal was in the car at some point (Argumentfrom Sign, see Walton et al. 2008). In addition to these general schemes, more (case-)
specific generalizations are also used as inference licences in Figure 1. For example, thetop inference is justified by the generalization ‘if person x was in a car at some time andsomeone looking like x has been seen in that car at time t, then it is likely that theperson in the car at time t was x’.
In the argumentative approach, the individual facts at issue are supported by theevidence in the case through arguments. The argument-based approach is inherently
dialectical: not only evidence supporting the probanda but also evidence against themshould be considered, and any sources of doubt in the arguments should be madeexplicit. The critical questions associated with the argumentation schemes in thearguments are a useful aid here, as they point to ways in which an argument based on ascheme can be attacked (Bex et al. 2003; Verheij 2003). Take, for example, the criticalquestions for the Witness Testimony scheme:
1. Was w is a position to know a?
2. Is w truthful??
3. Is w biased?
4. Is w’s statement that a internally consistent?
5. How plausible is w’s statement that a?
6. Is a consistent with what other witnesses say?

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These critical questions give pointers on how and where an Argument from Witness
Testimony might be attacked. For example, the third question asks if there is an
exception to the general scheme (i.e. normally, if a witness says something this is true
but in Bob’s case we have reason to believe this is not so because Bob is biased); thesixth question asks for other arguments (e.g. from another witness testimony that the
man in the car did not look like Pascal). Question 5 is interesting in that it asks for theinherent plausibility (i.e. irrespective of evidence) of the statement that someone wholooks like Pascal was in Nadia’s car. We will return to this inherent plausibility when
we discuss stories and story coherence below.
The argumentative approach is a dialectical way of reasoning with and about theevidence in a case. Argumentative reasoning has been called atomistic because thevarious elements of a case (i.e. facts, evidence) are considered separately and the case is
not considered ‘as a whole’. The approach builds on a significant academic tradition ofresearch on informal and formal argumentation and is well suited for a thoroughanalysis of the individual pieces of evidence and the inferences that can be drawn fromthem, using critical questions to probe the arguments for possible weak spots. However,
the atomistic nature of arguments makes them less suitable for giving an overview ofthe various hypothetical scenarios about what happened in the case.
2.2. The Narrative Approach
In the narrative approach, the facts of the case are organised into one or more stories:
coherent chronological sequences of events about what (might have) happened in thecase. In this approach, the evidential data in the case should be causally explained bysuch hypothetical stories through abductive inference. The basic idea of abductive
inference (see e.g. Walton 2001) is that if we have a general rule ‘c is a cause for e’ andwe observe e, we are allowed to infer c as a possible hypothetical explanation of theeffect e. This cause c which is used to explain the effect can be a single state or event,but it can also be a sequence of events, a story. Take, as an example, the observationthat Nadia is dead. According to the prosecution’s story, Nadia’s death was caused by
Pascal shooting her:

The arrows in the story-diagram in Figure 2 represent causal relations (whereas thearrows in the argument diagram in Figure 1 represent inferential relations) and thus theevents in the story causally explain the evidence in the case.
Abductive inference is a creative process, in which we use patterns ofcommonsense knowledge combined with observed evidence to form a number ofhypothetical scenarios. One aid in the abductive process is so-called story schemes,
general patterns of events that can serve as a background to particular stories. For
example, Pennington and Hastie (1993) present a scheme for intentional actions, acausal pattern of the form motive → goal → action → consequences. More specific74schemes were given by Schank (1986), who defines a number of explanation patterns
which may help in explaining events (or states) by connecting an event to an
explanation that has been used to explain similar events before. For example, the story
scheme for ‘murder’ is of the form person x has a motive m to kill person y → person x
kills person y (at time t) (at place p) (with weapon w) → person y is dead. In the Nadia
example, the murder scheme may be used to abduce a possible story from theobservation that Nadia is dead. The motive m would then be the disagreement and theweapon w a gun.
Taken by itself, abductive reasoning can seem to take the form of the fallacy ofaffirming the consequent. However, the apparent fallaciousness disappears if we
consider abductive reasoning in the broader context of inference to the best explanation(IBE): not just a single hypothetical story but also alternative scenarios are considered
and the best one is chosen. The choice between these alternative stories depends on how
well the individual stories explain the evidence and how coherent (Thagard 2004) eachof them is. The coherence of a story largely depends on whether the story conforms to
our general commonsense knowledge of the world, that is, whether we deem the story
to be inherently plausible (i.e. without considering the evidence in the case). Here, story
schemes play an important role (see Bex 2009). For example, a story is not sufficiently
coherent if there are parts missing; the murder story scheme mentions motives m and aweapon w and any murder story that does not explicitly mention a motive or a weapon
will be incomplete and hence less plausible. Furthermore, the causal relations in thestory scheme can be used to draw out the (implicit) causal relations in the story basedon the scheme; in the murder scheme, the motive causes the action (i.e. the killing), so
in a murder story there will also need to be such a causal link. Thus, the causal links canthen be further examined and questioned.
The narrative approach is a causal, dialectical way of reasoning withhypothetical stories that explain the evidence in a case. Clearly, this reasoning isdefeasible, since additional evidence might give rise to new explanations. Furthermore,
the narrative approach has been characterized as holistic (as opposed to atomistic),
because the stories allow the elements in a case (i.e. events, evidence) to be considered
as a whole. An important advantage of the narrative approach is that it is close to how
legal decision makers actually think about a case. Experiments by Pennington andHastie (1993) suggest that when reasoning with a mass of evidence, people compare thedifferent stories that explain the evidence instead of constructing arguments based onevidence for and against the facts at issue (as is done in the argumentative approach).
However, a disadvantage of the more holistic narrative approach is that the individual
pieces of evidence do not always have a clear place and the evidence’s relevance withregards to the facts at issue cannot be checked easily. Furthermore, it is not always clear
how one should reason about the coherence of a story and how stories should becompared.
2.3. The Hybrid Approach
Both the argumentative and the narrative approach concern reasoning about the facts
and the evidence: in the argumentative approach, the facts may be proven by justifying
them with arguments based on evidence, whilst in the narrative approach the facts are
justified by being part of a larger story that explains the evidence Bex (2011) shows thatwhen dealing with complex reasoning in criminal cases both the argumentative and thenarrative approach have their own advantages and disadvantages. The argumentative
approach, which builds on the philosophical tradition of argumentation, is well-suited75

for an analysis of the individual pieces of evidence, whilst the empirically-tested
narrative approach is appreciated for its natural account of crime scenarios and causal
reasoning. Conversely, the atomistic nature of arguments makes them unsuitable forgiving an overview of the various hypotheses about what happened in the case and not
all aspects of causal reasoning can be found in the argumentative approach. In the storybased approach, the individual evidence does not have a clear place and its credibility
and relevance cannot be checked easily. Arguments and stories therefore need to be
combined into one hybrid theory, where facts are organised into stories and arguments
based on evidence are used to support these stories. In other words, a story such as theone in Figure 2 should be anchored in evidence using arguments such as the one in
Figure 1, viz. Figure 3.
Main story
Pascal and Nadia had a disagreement. Pascal shot Nadia and thenfled in her car.

Sub-story
about thedisagreement

Sub-story:
Pascal shot Nadia and fled

Sub-story about
Pascal’s flightflatmates’
testimonies

Ballistics
reportBob

Policedog

Figure 3: A story anchored in evidence using arguments
In Figure 3 (adapted from Wagenaar et al. 1993),4 the main story is anchored in aground of evidence using arguments, which are based on argument schemes. Note how
the main story, which matches a general “kill and flee” scheme, is made up out of substories that match more specific story schemes lower in the hierarchy (e.g. a story
scheme about what happens when two people disagree, a “fight” story scheme about
what (may) happen when someone flees after committing a crime). Thus, botharguments and stories and their respective schemes have a clear place in the hybrid
theory.
The hybrid approach solves one of the most important issues with the narrative
approach as, for example, described by Wagenaar and colleagues (1993), namely that
often the connection between the evidence and the stories is not made clear. In the
hybrid approach, stories can be firmly anchored or, in other terms, evidentially
supported. Arguments can be attacked, which may break the “anchor’s chain”, causing
the story to be no longer connected to the ground. Note that stories can also be
evidentially contradicted using arguments. For example, an argument based on awitness statement saying that Pascal was in Poland when the shooting took place
contradicts the above story. Aside from anchoring stories in evidence, the hybrid
approach also makes it possible to reason about the coherence of a story in a dialectical76

way, as arguments can be given for the (in)coherence of a particular story or one of its
sub-stories. For example, if we take the story in Figure 2, where a relatively harmlessdisagreement is given as a motive for Pascal shooting Nadia, we could argue against thecausal link between the motive and the action by saying that ‘normally, people do notshoot other people when they have a disagreement’. This argument can itself be
attacked by saying, for example, that ‘Pascal is an aggressive person who does not react
to stress in the same way other people do’.
In the hybrid theory, stories can be used for constructing intelligible hypotheses
about what happened in an intuitive way and arguments can be used to connect theevidence to these stories and to reason about the stories and the evidence in greater
detail. In the next section, we will discuss how an anchored story (i.e. a combination ofstory and arguments) such as the one in Figure 3 can be analysed using a series ofcritical questions.
3. Critical questions for the hybrid theory: the Nadia van der V. case
Our hybrid argumentative-narrative approach to reasoning about the facts and theevidence gives rise to a number of critical questions that can be asked. These criticalquestions can be used to unearth sources of doubt in a total case (i.e. the combination ofarguments, stories and evidence) in the same way as critical questions for arguments
point to sources of doubt regarding a single inference. In this section, we will list these
critical questions and give some examples.
(CQ1) Are the facts of the case made sufficiently explicit in a story?
A case should contain a clearly phrased, sufficiently specified and coherent story
detailing “what happened”.
The starting point of a well-supported opinion about the facts is a concrete story about
what happened, that is, a clear and sufficiently specific chronological account of what(might have) happened in a criminal case. By presenting the story separately from anyarguments about its plausibility and the evidence, the coherence of the story can be best
appreciated and investigated. In a sense, one can say that this story is the conclusion of
the argument about the case-as-a-whole (cf. the analysis by Verheij and Bex 2009).
Which stories can be the conclusion of a legal verdict is often restricted by formal
constraints; for instance, in the Netherlands the factual account of a conviction shouldmatch the indictment presented by the prosecution. In the Nadia case, the prosecution’s
main story was roughly as follows:
Nadia and Pascal had a disagreement about a washing machine and Pascal
decided to kill Nadia. He called his work to report in sick and grabbed his Uzi, asmall machine gun he had in his room. Pascal then shot Nadia twice, dragged
her to the kitchen and killed her by shooting again at close range. Pascal then left
the house and fled in Nadia’s car.
For now, we regard this (simple) story as a sufficient answer to CQ1 and turn to CQ2.
(CQ2) Does the story conform to the evidence?
a. Is the story sufficiently supported by the evidence in the case?
b. Is the story contradicted by evidence in the case?

77

One's belief in the truth of a story about what happened must be supported by evidence.
A key step is the identification of the evidential support that can be given for theelements of a story, that is, identifying the sources of evidence that support the story. In
the Nadia case, many events in the story are explicitly supported by evidence: Pascal's
colleague testified that Pascal called in sick; there were bloodstains, bullet parts andshells in the corridor and an Uzi's sawn-off barrel, cartridges and cartridge clip were
found in Pascal's room; a telephone conversation between Pascal and his father wasintercepted, in which Pascal said that he killed Nadia; a statement by Pascal's father,
who claimed that Pascal had told him about a disagreement between Nadia and Pascal
and that Pascal went crazy because he had been drinking; witnesses stated they saw
someone looking like Pascal drive Nadia’s car and scent tests showed Pascal had beenin the car (Figure 1). This list of evidence is taken directly from the verdicts, where they
are largely listed in chronological story order.5
In general, not all elements of a story can be supported by evidence. This does
not need to be a problem, and is in fact unavoidable as certain story elements must by
their nature be indirectly justified. When an element of a story is not supported by apiece of evidence (in a given argument), we speak of an 'evidential gap'. In the verdicts
on Nadia's murder, the main evidential gaps seem to be not the events in the story but
rather some of the causal relations in the story. For example, exactly why the(seemingly trivial) disagreement caused Pascal to shoot Nadia is at first left unexplained
and no evidence is mentioned for the fact that the shooting caused Nadia’s death. In
some cases, such as Pascal’s motives for the murder, these causal relations are dealt
with separately below (e.g. when looking at the plausibility of the story, see CQ4).
Other causal relations, such as the cause of death, can probably be supported on thebasis of autopsy report on Nadia's body, but this is not mentioned in the verdicts
because it was no issue in the case. In sum, CQ2 has been satisfactorily answered.
The existence of evidential gaps, here conceived of as parts of a story for which
no direct evidence6 is available, is one reason why a mixed-argumentative narrative
perspective can be useful. The analytical argumentative perspective makes theevidential gaps visible, the narrative perspective shows why the evidential gaps can still
be believed in conjunction with other facts. In general, it is a matter of good judgment
which elements of a story must be directly supported by evidence and which can beinferred from other facts. This depends in part on the quality of the evidence (a story
supported by weak evidence can become stronger by providing evidence for morefacts), but also on the nature of the crime and the law.
In addition to looking at how much of the story is supported, one should also
consider how much of the total evidence in the case supports the story. If, for example,
a story is completely supported by 2 witness testimonies but there are 20 more
witnesses who state another (incompatible) story, the story does not sufficiently
conform to the evidence in the case even though there are no gaps in it. Furthermore,
one should also take into account the amount of evidence that directly contradicts astory; instead of giving an alternative story (see CQ5 below), the opposing party may
simply deny elements of the main story. For example, in the Nadia case the defence
might have witnesses that state that there was never a disagreement and that Pascal andNadia were good friends. In this case, however, such arguments were not made and weturn to the next critical question.
(CQ3) Is the support that the evidence gives to the story sufficiently relevant
and strong?

78

a.
b.

Are the reasoning steps from evidence to events in the story justified bywarranting generalizations and argument schemes that are sufficiently
strong and grounded?
Are there exceptions to the use of the generalizations and schemes that
undermine the connection between evidence and fact?

In order to determine relevance and probative force of a piece of evidence, thegeneralizations and schemes warranting the inference steps should be made explicit.
Thus it can, for example, become clear that the generalization is false and cannot be thebasis for a good reasoning step. In general it will therefore be important to determine
whether and, if so, on which grounds a generalization is considered to be valid (i.e.
provide the backing to the warrant, Toulmin 1958). For example, the witness testimony
scheme can be grounded in the law (e.g. article 339, Dutch code of Criminal
Proceedings says that a witness’ testimony is a valid source of evidence). Schemes orgeneralizations can have other sources than the law:7 we often make inferences
warranted by generalizations which are based on general knowledge (Cohen 1977).
Such generalizations are necessary but also dangerous (Twining 1999), as they might
express implicit biases or prejudices we hold (e.g. “a confession is often true”, cf.
Wagenaar et al. 1993). In the example of the murder of Nadia, we see that most
reasoning steps are based on plausible generalizations and schemes. Perhaps the use ofscent tests as a basis for drawing conclusions is the most controversial.8 If we consider
criticism concerning scent tests as a forensic investigative procedure as well founded,then we must conclude that scent tests cannot be used to support conclusions (CQ3a).
With respect to most of the listed pieces of evidence, we need not assume that there
are exceptions to the underlying generalizations or schemes (CQ3b) and we can infer
the events of the story supported by the evidence. One exception here is Pascal's father’s
testimony: it might very well be possible that the father is biased when testifying about
his own son (critical question 3 for the Witness Testimony Scheme). However, in thiscase there was also other evidence pointing in the same direction (the intercepted
telephone conversations) so it seems that Pascal’s father told the truth in this case.
Now that we have considered critical questions 1, 2 and 3, we are in the following
position: there is a sufficiently clearly delineated account of the facts (the story), of
which as many events as possible have evidence supporting them, and of which therelevance and strength has been established as well as possible. The argument about thecase as-a-whole can be further improved by showing that the story is plausible in itself.
(CQ4) Has the story itself been sufficiently critically assessed?
a. Is the story sufficiently coherent? Are there required elements missing? Are
there implausible events or causal relations? Is the story inconsistent?
b. Have story consequences been used to test the story?
First, the story's coherence must be examined (CQ4a). Here coherence has a specificmeaning, namely that the story fits our knowledge and expectations about the world welive in. In other words, a story should be complete (i.e. have all its essential parts) andplausible (i.e. have plausible causal relations). In section 2.2 it was already argued thatstory schemes play an important role in determining a story’s coherence; completeness,for example, is relative to a particular scheme. A story should also be consistent; forinstance, when the story implies that the suspect was simultaneously at two different
places it is incoherent.

79Something that at first sight is implausible in the story about Nadia's murder isthe assumption that disagreements over the washing machine led Pascal to murder
Nadia. In other words, the relationship between the motive (the disagreement) andPascal's action (murdering Nadia) is implausible. No reasonable person would assume
that disagreement over washers and driers commonly leads to an intention to murder
someone. However, in its decision, the court of appeal inadvertently elaborates on
Pascal's tendency to react rather violently in response to what most consider to be futile
causes. In the decision, a psychiatric report is discussed; it is used to provide support forthe decision to keep Pascal under psychiatric surveillance. The report explains that
Pascal has a disorder by which ordinary events make him feel seriously threatened andreact with disproportionate violence, which makes the events surrounding the death ofNadia and its cause more credible. This shows that a seemingly incoherent story canstill be believed when supported by evidence.9
A further way of testing a story is to look for possible reasons against facts that
follow from the story (story consequences, CQ4b). For example, if we assume that theperpetrator, whoever it may be, has shot Nadia at close range and that he has
subsequently dragged her body to another place, it is highly likely that he has blood on
his hands, clothes and shoes. If the offender then stepped into her car, there should betraces of Nadia's blood in or on the car. The ruling of the court stated that there wasblood on the door lock and the floor mat on the driver's side of the car; a comparative
DNA analysis showed that the profiles of the blood found in and on the car matched
Nadia's profile.
In sum, the prosecution’s main story seems sufficiently coherent and CQ4 gives
no problems. However, besides the critical assessment of the main story, the conclusionof the argument in the case as-a-whole, sufficient attention should also be paid topossible alternative scenarios of what has happened.
(CQ5) Have alternative stories been sufficiently taken into account?
a. Has a sufficient search for alternative explanations been performed, not onlyin the investigative phase, but also in court?
b. Are there good reasons to choose one story over the alternatives? Have thealternatives been sufficiently refuted?
First a serious search for alternative scenarios is needed. In part, the opposing party inthe process will provide alternatives, but a decision maker will also have to actively
consider different accounts of what may have happened. These alternatives should not
only be actively sought, they should also be adequately refuted: essentially, all thecritical questions that can be asked for the main story also have to be asked for thealternatives.
In the Nadia case, Pascal told the alternative story that he was suffering fromamnesia and could not remember what happened the day Nadia died. He claimed tohave been kidnapped and taken to Poland, although by unknown persons and for
unknown reasons. This can hardly be considered a story (cf. CQ1 that requires asufficiently specific account of the facts), but as an argument against the prosecution’s
story that is not necessary: such a refutation can take the form of a simple claim(supported by evidence) that the suspect was somewhere else than at the scene of thecrime. However, it makes the suspect's case stronger when he can present a wellsupported and coherent story. In the present case, Pascal’s story is not nearly as
coherent and well-supported as that of the prosecution. Several crucial elements are
missing (completeness, CQ4a), such as the identity and motive of the kidnappers.

80Furthermore, there was no evidence of the kidnapping having taken place (CQ2). Also,
the court explicitly addresses the amnesia defence: it states it does not believe Pascal,
because Pascal has never sought medical help for his alleged amnesia. Thus, the court
explicitly refutes Pascal’s alternative (CQ5b).
Finally, a general caveat is in place: any conflicting reasons must be weighed.
(CQ6) Have all opposing reasons been weighed?
Have all considerations that are used to weigh opposing reasons been madeexplicit? Has this been done both at the level of individual facts and events andat the level of stories?
For example, if two witnesses make opposite statements about the presence of thesuspect, both statements provide a reason, one supporting the suspect’s presence, theother against. When there are explicit grounds that can decide the weighing of suchopposing reasons, they should be given. The stronger and more relevant the reasons are,the more important it is to decide explicitly how they are weighed against each other.
Conflicting reasons do not only exist at the level of individual events, but also at thelevel of stories. For example, there might be reasons for and against a story as a whole.
It can occur that significant elements of a particular story are supported by evidence,
while the story itself is rather incoherent. The weighing of reasons then takes the formof deciding whether the story is sufficiently justified by the evidence and how it
measures up to the alternatives.
In the Nadia case, there was no difficulty in the balancing of reasons at the levelof stories. Pascal’s “story” was so implausible and badly supported that it could beconsidered as refuted by itself, even without considering the plausible and wellsupported story of the prosecution. There was no need to weigh any reasons on the levelof individual events, as no arguments were given that directly refuted any of thearguments of the prosecution.
4. Conclusion
In this paper, we have proposed a series of critical questions for the hybrid
argumentative-narrative theory of reasoning about the facts and the evidence in legal
cases. Some of the critical questions correspond closely to argumentative approaches toreasoning with evidence (in particular critical question 2 about the sufficient support ofthe events, and question 3 concerning the relevance and strength of the support). There
are also questions that are strongly connected to a narrative style of analysis (inparticular question 4 about the coherence of the supported story, and question 5 about
the consideration of alternative stories). But there are also questions that have a more
hybrid position between argumentation and narrative. For instance, critical question 1
requires that an argument about the facts has a specific story as a conclusion, andquestion 6 considers the weighing of the pros and cons for individual events and forcomplete stories.
We have used the analytic tool of the critical questions associated withargumentation schemes as studied in argumentation theory (recently by Walton et al
2008, building on work by Perelman and Olbrechts-Tyteca 1958, Hastings 1963 andKienpointner 1992). We have extended the use of critical questions to questions forstories and the schemes on which they are based, and for hybrid structures ofarguments, stories and evidence.

81One of the lessons learned from the work on the hybrid theory is that stories andarguments are essentially “communicating vessels”: when dealing with the complex
reasoning involved in large criminal cases, a narrative approach works best for somepoints of a case, while in other instances an argumentative approach is most natural.
However, for a deeper understanding of the connection between argumentation andnarrative, it seems to be required to develop a genuine integration of both. Meanwhile,
our hybrid approach allows for the flexibility of the separate argumentative andnarrative approaches whilst at the same time it uses arguments and stories ascomplementary tools for complex reasoning. The case studies in this text and anotherone by Bex (2011) accentuate the value of a hybrid, argumentative-narrative analysis ofreasoning about the facts in criminal cases.
NOTES
1

We use the term “fact” in its juridical sense, that is, descriptions of states or events thetruth of which is currently unknown and has to be proven (cf. facta probanda or facts at
issue, Anderson et al. 2005). Thus, reasoning about the facts is essentially determining“what happened” in the case. With “evidence” we mean the evidential data, the primarysources 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 truthof the fact evidenced. For example, that there is a testimony by a witness who saw thesuspect jump into a car does not guarantee that the suspect jumped into a car (thewitness might lie or he might confuse the suspect with someone else).
2
Bex and Verheij 2009 was written in Dutch and specifically aimed at legal
professionals. In this paper, we have adapted the critical questions and example case foran academic audience.
3
In the Netherlands the judges are required to provide a written verdict in which theirconsiderations 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 (inDutch): LJN AO3150 (court of Utrecht) and LJN AT5190 (court of appeals Arnhem).
4
Wagenaar, van Koppen and Crombag (1993) propose the theory of anchorednarratives and use it to explain 'dubious cases', i.e. possible miscarriages of justice.
Verheij (2000) draws analogies between this approach and argumentative approaches
and Verheij and Bex (2009) have reconstructed the theory in terms of argumentation
schemes. Our Figure 3 is similar to the one by Wagenaar, van Koppen and Crombag(1993, p. 39), but there is a crucial difference between our figure and that of Wagenaar
et al.: we use the evidence as the firm ground to anchor onto, whereas in anchorednarratives theory commonsense generalizations provide the anchors.
5
Pennington and Hastie (1993) have shown that the chronological ordering is moreconvincing than an arbitrary ordering.
6
There is theoretical discussion about the nature and existence of direct evidence, seefor instance Anderson, Schum and Twining (2005), pp. 62-63. For our purposes, itsuffices 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.
7
Freeman (2006) has provided a classification of types of warrants based on epistemic
considerations. He distinguishes a priori, empirical, institutional and evaluative
warrants.

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8

The tests raised controversy in another well-publicised Dutch case, namely the socalled Deventer Moordzaak.
9
It is important to emphasize that the decision about the belief in a story must first andforemost depend on the evidence available and not the story’s coherence, that is, a“good” story should never be preferred to a “true” story (Bennett. and Feldman 1981).
REFERENCES
Anderson, T.J., Schum, D. A., & Twining, W. L. (2005). Analysis of Evidence, 2ndedition. Cambridge: Cambridge University Press.
Bennett, W.L., & Feldman, M.S. (1981). Reconstructing Reality in the Courtroom:
Justice and Judgment in American Culture. London: Methuen-Tavistock.
Bex, F.J. (2009). Analysing stories using schemes. In H. Kaptein, H. Prakken & B.
Verheij (Eds.), Legal Evidence and Proof: Statistics, Stories, Logic (pp. 93–
116). Aldershot: Ashgate Publishing.
Bex, F.J. (2011) Arguments, Stories and Criminal Evidence: A Formal Hybrid Theory.
Dordrecht: Springer.
Bex, F.J., Prakken, H., Reed, C., & Walton, D.N. (2003). Towards a formal account of
reasoning about evidence: argumentation schemes and generalisations. Artificial
Intelligence and Law, 11, 125–165.
Bex, F.J., Prakken, H., & Verheij, B. (2007). Formalising argumentative story-based
analysis of evidence. Proceedings of the 11th International Conference on
Artificial Intelligence and Law, (pp. 1–10). New York (New York): ACM Press.
Bex, F.J., van Koppen, P.J., Prakken, H., & Verheij, B. (2010). A Hybrid Formal
Theory of Arguments, Stories and Criminal Evidence. Artificial Intelligence andLaw 18 (2), 123-152.
Bex, F.J., & Verheij, B. (2009). Het onderbouwen van een feitelijk oordeel in een
strafzaak: methode, casus, aanbevelingen (Grounding a judgement about thefacts in a criminal case: method, case, recommendations). In P.J. van Koppen,
H. Merkelbach, M. Jelicic & J.W. de Keijser (Eds.), Reizen met mijn Rechter:
Psychologie van het Recht (pp. 935–952). Deventer: Kluwer.
Cohen, L.J. (1977). The Probable and The Provable. Oxford: Oxford University Press.
Freeman, J. B. (1991). Dialectics and the Macrostructure of Arguments: A Theory of
Argument Structure. Berlin: Foris Publications.
Freeman, J.B. (2006). Systematizing Toulmin’s Warrants: An Epistemic Approach. In
D.L. Hitchcock & B. Verheij (Eds.), Arguing on the Toulmin Model. New Essays
in Argument Analysis and Evaluation (pp. 87–10). Dordrecht: Springer-Verlag.
Hastings, A. (1963). A Reformulation of the Modes of Reasoning in Argumentation.
Doctoral dissertation, Northwestern University.
Kienpointner, M. (1992). Alltagslogik: Struktur und Funktion von Argumentationsmustern. Stuttgart-Bad Cannstatt: Frommannn-Holzboog.
Loui, R.P. (1995). Hart's critics on defeasible concepts and ascriptivism. Proceedings ofthe 4th International Conference on Artificial Intelligence and Law (pp. 21–30).
New York (New York): ACM Press.
Perelman, C., & Olbrechts-Tyteca, L. (1971/1958). The New Rhetoric: A Treatise on
Argumentation. University of Notre Dame Press: Notre Dame/London. French
original first published in 1958.
Pennington, N., & Hastie, R. (1993). Reasoning in explanation-based decision making.

83

Reed, C., Walton, D. & Macagno, F. (2007). Argument diagramming in logic, law andartificial intelligence. Knowledge Engineering Review, 22 (1), 87–109.
Schank, R.C. (1986). Explanations Patterns: Understanding Mechanically andCreatively. Hillsdale (New Jersey): Lawrence Erlbaum.
Thagard, P. (2004). Causal Inference in Legal Decision Making: Explanatory
Coherence vs. Bayesian Networks. Applied Artificial Intelligence 18 (3), 231–
249.
Toulmin, S.E. (1958). The Uses of Argument. Cambridge: Cambridge University Press.
Twining, W.L. (1999). Necessary but Dangerous? Generalizations and Narrative in
Argumentation about 'Facts' in Criminal Process. In J.F. Nijboer & M. Malsch(Eds.), Complex Cases: Perspectives on the Netherlands Criminal Justice
System (pp. 69–98). Amsterdam: Thela Thesis.
Verheij, B. (2000). Dialectical Argumentation as a Heuristic for Courtroom Decision
Making. In P.J. van Koppen and N. Roos (Eds.) Rationality, Information and
Progress in Law and Psychology. Liber Amicorum Hans F. Crombag (pp. 203–
226). Maastricht: Metajuridica Publications.
Verheij, B. (2003). Dialectical argumentation with argumentation schemes: An
approach to legal logic. Artificial Intelligence and Law 11 (2), 167–195.
Verheij, B., & Bex, F.J. (2009). Accepting the Truth of a Story About the Facts of a
Criminal Case. In H. Kaptein, H. Prakken & B. Verheij (Eds.) Legal Evidence
and Proof: Statistics, Stories, Logic (Applied Legal Philosophy Series) (pp. 161193). Farnham: Ashgate.
Wagenaar, W.A., van Koppen, P.J., & Crombag, H.F.M. (1993). Anchored Narratives.
The Psychology of Criminal Evidence. London: Harvester Wheatsheaf.
Walton, D.N. (2001). Abductive, presumptive and plausible arguments. Informal Logic
21 (2), 141–172.
Walton, D.N. (2002). Legal Argumentation and Evidence. University Park
(Pennsylvania): Penn. State University Press.
Walton, D.N., Reed, C.A., & Macagno, F. (2008). Argumentation Schemes. Cambridge:
Cambridge University Press.
Wigmore, J.H. (1931). The Principles of Judicial Proof or the Process of Proof as
Given by Logic, Psychology, and General Experience, and Illustrated in Judicial
Trials, 2nd edition. Boston (Massachusetts): Little, Brown and Company.

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