The Systematic Assessment of Risk for Aggressive and Violent Behaviour against Others

• Author: Christopher Webster, Carla R. Dassinger, and Hy Bloom
• Pages: 465-484

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CHAPTER 23

The Systematic Assessment

of Risk for Aggressive and

Violent Behaviour against Others

Christopher Webster, Carla R. Dassinger, and Hy Bloom

I. INTRODUCTION

Peter Scott, the distinguished British forensic psychiatrist, remarked over thirty years ago that, “we can-

not at present hope, by taking innitely careful aim to direct our dangerous patient to safety like an

arrow to its target. . . .” (1977). is observation holds true today. Yet substantial advances have been

made since he published his article on dangerousness. For one thing, the concept of dangerousness has

now disappeared from the clinical and research literature. It has been replaced by the notion of risk.

Risk, in contrast to dangerousness, implies that the level of potential violence may vary not only accord-

ing to factors that inhere within the individual (e.g., level of anger, a mount of intelligence, etc.), but also

according to factors that apply to the physical and social environments (e.g., the availability of material

resources, family or professional support, employment opportunities, rehabilitation services, and so on).

Scott was somewhat dismissive of so-called actuarial devices according to which future violence

may be predictable to some extent by referring to statistical studies which aim to show the strength of

particular, closely-dened, predictor variables (i.e., by linking them to actual follow-up data obtained

months or years later). In recent years it has been shown that certain actua rially broad schemes yield im-

portant information about the kind of factors that contribute, statistically, to relapse into mental disorder

and violent recidivism. Assessors need to be aware of this literature and, when appropriate, view their

particular case in light of this kind of information. Certainly, they stand to be examined on this point

when appearing before courts and tribunals.

At the same time that knowledge has accumulated about actuarial prediction, so too has an ap-

proach called “structured professional judgment” (SPJ). e best-known of the devices, designed for use

in civil, forensic, and correctional settings, is the Historical/Clinical/R isk Management-20 (HCR-20;

Webster, Douglas , et al., 1997). is scheme invites assessors to organize their risk ev aluations according

to historical considerations (ten dened items), current clinical states (ve dened items), and futu re risk

management issues (ve dened items). Although scores from the various items can be tallied (twenty

items, each scored as zero, not present, one, present to some extent, and two, present), no normative data

are presented. Rather, with the assessment complete, the evaluator postulates the risk or risks to be low,

moderate, or high. In other words, relevance is upon overall clinical judgment, which ideally species

which risks will be ev ident, of what levels of seriousness, against whom, under what conditions, and over

what periods of time.

Considerable debate has occurred between strong proponents of the actuarial approach (who will

argue, for example, that there is no evidence that clinical judgment improves material obtained from

carefully coded le information) and the SPJ point of view (who will argue that, oentimes, the assessee

under evaluation is not represented within the population upon which the particular actua rial approach

was standardized). A helpful review of the clinical versus actuarial debate is given by Litwack (2001).

e authors of the present chapter hold that those who assess violence risk must be fully cognizant

of both approaches and that they should put themselves in position to be an expert in both the actuarial

Christopher Webster, Carla R. Dassinger, and Hy Bloom

and SPJ approaches. is entails a good deal of study of texts and manuals (including, importantly, the

Hare 2003 PCL-R scheme for evaluating psychopathy, since this instrument has become of central im-

portance in both actuarial and SPJ evaluations).

II. THE RISK ASSESSMENT

Psychiatrists and other mental health professionals tend to deal with risk assessment in three main ways:

• on an emergency basis where they themselves have to make urgent decisions for the present and

short-term f uture;

• in an advisory capacity to crimina l lawyers, prosecutors, courts, and tribunals of various kinds; or,

• on occasion, as members of formally constituted decision-making review boards.

A. Centrality of Legal Requirements

Psychiatrists have to oer opinions about potential violence risks at many junctures within the psychiat-

ric, forensic, and correctional spheres. Since civil commitment takes place under mental health law, and

since such statutes vary from province to province, assessors need to have a clear understanding of the

legal requirements for involuntary commitment to hospital, or in certain jurisdictions, to the community

(Swartz et al., 1999). e idea of community certication, which is of relatively recent origin, is to allow

the client to live as normal and as unimpeded a life as possible but yet be subject to specied conditions

some of which would prevent an immediate return to hospital. Grounds for certication, both those for

regular inpatient detention and those for community supervision, are stipulated in law, as are reasons for

decertication, the eect of lapsing certicates, and the appeal procedures for those who elect to protest

against continuing restriction. ese need to be thoroughly understood as do certain highly inuential

caselaw ndings. Elsewhere, we have argued that knowing the law, and following it, is arguably the most

important aspect of all when it comes to assessing violence risk (Webster et al., 2002; Webster & Hucker,

2003). Even highly seasoned psychiatrists are advised to refresh their memories of the pertinent law prior

to undertaking a new assessment case because evaluators must use quite dierent approaches to assess-

ments depending upon the legally-stipulated reason for remand or assessment. Giving an opinion about

release on bail can be relatively simple (when all of the relevant facts are on hand; see Chapter 11: Bail

and Mentally Disordered Accused); oering expert testimony as to whether or not an individual quali-

es for an insanity defence or designation as a Dangerous Oender will require much more detailed and

protracted evaluations.

Psychiatric expertise in risk assessment is called upon in many dierent legal circumstances. While

dangerousness is not usually a central component of an evaluation of an accused for the purpose of

determining his tness to stand trial, the issue may become relevant when the court has to make a

determination as to where an assessment should take place, and when deciding whether to release the

individual into the community on bail until the court hears the question of tness.

Once an accused has been found unt to stand trial or not criminally responsible on account of men-

tal disorder (NCR) under the Criminal Code, he falls under the jurisdiction of the review boards charged

with deciding if and when a release is appropriate. Psychiatrists are involved in this process in either of

two ways: they may appear before the boards as an assessor or as a treatment provider to give an opinion

about a patient under their care. e federal law also requires that at least one psychiatrist sit on each

review board. In this capacity they provide expertise in violence risk assessment and appraise evidence

concerning the accused’s risk for violence.