Measuring and Predicting Police Caution Comprehension in Adult Offenders
In Canada, individuals detained by a police officer for questioning about their potential involvement in criminal activity are typically informed about their right to silence and their right to access legal counsel, both of which are guaranteed by the Charter of Rights and Freedoms (the Charter) (1982). It is imperative that detainees comprehend the two sets of rights fully because it ensures that (a) their decision to talk to the police is voluntary and based on an informed understanding of their rights and (b) any statement obtained by the police interviewer and subsequent evidence obtained from the statement are admissible in court (e.g., Marin 2004). Although research has shown that university students struggle to comprehend the content of police cautions (i.e., passages of text that contain the legal rights just described) (Eastwood and Snook 2010; Moore and Gagnier 2008), no research has examined how well adult Canadian offenders understand these cautions or what factors affect their comprehension. In the current study, we measure caution comprehension in a sample of offenders and predict comprehension levels with three measures of cognitive ability.
The rights afforded to detainees in Canada are contained in the Charter and include the right to silence and the right to legal counsel. The right to silence is derived from section 7 of the Charter and includes the imperative that detainees must be given a choice whether or not to speak to the police and that the police cannot do anything to interfere with this right (e.g., offer threats or promises in exchange for a statement; see R v Hebert 1990). The right to legal counsel is contained in section 10(b) of the Charter and states that, upon arrest or detention, individuals have the right to retain and instruct legal counsel without delay. As outlined in subsequent case law, the right to legal counsel has four main components: (a) to retain legal counsel without delay, (b) to have immediate access to duty counsel and to obtain legal advice free of charge, (c) to have information about how to access these services, and (d) to have access to a Legal Aid lawyer if the suspect meets the financial criteria set by the government (R v Bartle 1994; R v Brydges 1990).
Although interviewers are only required to deliver the legal counsel caution, both cautions tend to get delivered (Snook, Eastwood, and MacDonald 2010). Due to the power differential between a police officer and a detainee, legal rulings have stipulated that an interviewee can only waive his or her rights if s/he does so voluntarily, without intimidation, coercion, or deception. For a decision to be considered voluntary, detainees must also have full knowledge of their legal rights and appreciate the consequences of waiving those rights (Clarkson v The Queen; Korponay v Attorney General of Canada). As mentioned, a failure to show that a detainee understood their rights means that the person's rights were not being protected and that any statement taken--and further evidence collected as a result of that statement (e.g., using what the detainee says to obtain a search warrant that ultimately produces incriminating evidence)--may be ruled inadmissible in court (see Marin 2004).
In one of the first attempts to measure the comprehension of Canadian cautions, Moore and Gagnier (2008) found that comprehension levels of university students was similar across four versions of a right to silence caution. They found that only 43% of the students demonstrated full comprehension and 15% did not understand any of the caution. A similar study by Eastwood and Snook (2010) found that only 4% understood the right to silence caution fully when presented verbally in its entirety. When it was presented in written, sentence-by-sentence format, 48% of participants understood the entire caution. For the legal counsel caution, only 7% displayed full comprehension when the caution was presented verbally in its entirety, but 32% of participants understood it fully when it was presented in written, sentence-by-sentence format. A third study, which presented three groups of university students with legal counsel cautions that varied in complexity, found that, regardless of the complexity of the caution received, participants comprehended approximately 30% of their legal rights (Eastwood, Snook, and Chaulk 2010). Eastwood et al. also reported that only 23% of participants comprehended more than half of their legal rights. The central message from these studies is that comprehension of Canadian cautions is inadequate.
The samples used in past studies of police caution comprehension have consisted of university students. It remains unknown whether or not the results found in those studies generalize to offenders. On the one hand, most offenders have had experience with the cautions and the justice system and it would seem reasonable to assume that this exposure would lead to increased understanding of their rights and how to exercise them. On the other hand, the comprehension of legal rights by offenders may be hindered by the fact that such individuals are more likely to have, singly or in combination, mental illness, intellectual disabilities, learning disabilities, and low education and literacy levels (e.g., Haigler, Harlow, O'Connor, and Campbell 1992; O'Connell, Garmoe, and Goldstein 2005; Teplin 1994). Although no research exists in a Canadian context, research from the United States and the United Kingdom suggest that the latter explanation may be most accurate (e.g., Fenner, Gudjonsson, and Clare 2002; Grisso 1981).
An original set of studies by Grisso (1981) examined Miranda comprehension in juvenile and adult offenders. Grisso's results showed that only 21% of the juveniles and 42% of the adults understood the entire Miranda warning that was presented to them. A second study of Miranda comprehension using defendants recruited from a state hospital showed a similarly low level of comprehension of the legal rights contained in the warnings (Rogers, Harrison, Hazelwood, and Sewell 2007). Research from the United Kingdom has shown an even lower level of comprehension of their police caution. For instance, one study showed that not a single suspect was able to demonstrate a complete understanding of her or his rights (Fenner et al. 2002). Similar findings have been reported in other studies carried out in England (Clare, Gudjonsson, and Harari 1998) and Scotland (Cooke and Philip 1998). Given that providing cautions and warnings to suspects before questioning is mandatory in all these countries, previous involvement with the justice system does not appear to lead to an increase in comprehension.
Along with the complex nature of the cautions themselves (e.g., Eastwood et al. 2010; Rogers, Harrison, Shuman, Sewell, and Hazelwood 2007), one explanation for the low level of comprehension in offenders seen in previous studies has been the role of various cognitive factors. For example, in the study by Grisso (1981) mentioned earlier, overall IQ was a strong predictor of the level of Miranda warning comprehension (also see Everington and Fulero 1999). Research has also shown that Verbal IQ is related to police caution comprehension (Cooke and Philip 1998). In addition, some symptoms of psychopathologies such as schizophrenia and substance abuse which are over-represented in prison populations (Teplin 1990)--are associated with...