Mandatory Minimum Penalties: Their Effects on Crime, Sentencing Disparities, and Justice System Expenditures

4. Can offenders be deterred? (continued)

4. Can offenders be deterred? (continued)

4.3 Evidence on Deterrence and Incapacitation

Research on the deterrent and incapacitative effects of punishment in general can shed some light on the potential preventive effects of MMS. One issue is whether minimum penalties are actually imposed consistently and hence increase the certainty of punishment. Also, assuming that MMS increase sentence length, do potential or actual offenders differentiate between sentences of, say, five and seven years in their decision to commit a crime? Legal sanctions that dissuade the general population from offending are referred to as general deterrents, while those dissuading actual offenders from repeating their crimes are called specific deterrents. Furthermore, do lengthier sentences continue to provide preventive benefits through incapacitation; or, might they provide diminishing returns, as incapacitated individuals age and other offenders replace them in the illicit marketplace?

4.3.1 Deterrence

There is a voluminous research literature on these matters. Criminal sanctions have been found to carry some deterrent and incapacitative effects (Canadian Sentencing Commission, 1987; Nagin, 1998); however, these effects vary according to a number of factors, including:

  1. The nature of the crime. Deterrent effects may be crime-specific. One study, for example, found that the increased certainty of arrest helped lower the burglary rate, while larceny rates were unaffected by police efforts (Zedlewski, 1983);
  2. The target group. The link between the certainty of punishment and crime rates may also vary according to criminal history or race (Greenfield, 1985; Wu and Liska, 1993). More persistent offenders and those who have been punished in the past are less likely to be deterred by the threat of punishment and each ethnic/racial group tends to respond to the arrest probability of members of that group, rather than to society-wide arrest probabilities;
  3. Moral prohibitions associated with the behaviour. Those who will experience shame or embarrassment as a result of their involvement in a crime are less likely to commit that crime (Grasmick, Bursik, and Arneklev, 1993);
  4. Knowledge of the pertinent sanction. The public has little knowledge of the nature and severity of criminal sanctions, including those offences carrying MMS (Canadian Sentencing Commission, 1987). The awareness of legislative change, such as the introduction of a MMS, is an obvious prerequisite to its marginal deterrent effect;
  5. The certainty of punishment. Some studies show that crime rates decline with an increase in the probability of arrest (Tittle and Rowe, 1974; Marvell and Moody, 1996);
  6. The celerity or swiftness of punishment (Howe and Brandau, 1988). While little evidence exists in relation to this factor, learning theories suggest that the more swiftly punishment follows a crime, the lower the likelihood that the crime will be repeated;
  7. The severity of the sanction. While some studies show that tough sanctions carry a deterrent effect (Green, 1986), the evidence relating to this factor is mixed at best;
  8. Perceptions of the risk of incurring the sanction (Klepper and Nagin, 1989). Generally, those who believe they are likely to be caught and punished will be less likely to commit a criminal act.

The many factors shaping the potential deterrent effect of criminal sanctions preclude simplistic, sweeping generalizations affirming the presence or absence of a deterrent effect. The evidence bearing on the issue of deterrence is very complex and incomplete. Hence, extreme positions either denying the existence of any deterrent effect of legal sanctions or suggesting that everyone can be deterred reflect entrenched ideological positions, rather than the empirical evidence.

The research on both sentence certainty and severity are relevant to MMS and, on balance, the evidence suggests that severity may be less critical to deterrence than initiatives boosting the certainty of punishment (Miller and Anderson, 1986; von Hirsch et al., 1999). In fact, these elements often operate at cross-purposes as actors within the criminal justice system have been known to circumvent laws they believe are draconian by failing to charge or by refusing to convict guilty defendants (Ross, 1982). Thus, excessively harsh penalties may undermine the certainty of punishment by reducing the risk of incarceration. Conversely, increases in the certainty of imprisonment can produce compensating reductions in sentence lengths. A US study of incarceration in six states found that, for drug offences and robbery, an increase in one was compensated for by reductions in the other (Cohen and Canela-Cacho, 1994). As prison capacity, at any time, is finite, increasing the rate of incarceration for one group of offenders may necessitate shorter sentences or early releases of other offenders. There may be important lessons here with regard to MMS.

As MMS often apply to repeat offenders, research on specific deterrence, the extent to which known offenders respond to the threat and experience of punishment, is particularly relevant. The high recidivism rates generally found among former prisoners and studies of the impact of custodial sanctions on young offenders leave little room for optimism regarding specific deterrence (Siegel and McCormick, 1999:). The specific deterrent effect may be limited, but it is not nil. A study of career armed robbers who had abandoned their life in crime revealed that one of the key factors underlying their decision was a desire to avoid further incarceration (Gabor et al., 1987). For some offenders, at least, there may be a point at which they tire of punishment and its associated privations.

A survey of 1,000 convicted felons suggests that even serious offenders do not become completely inured to the effects of punishment (Horney and Marshall, 1992). The study revealed that subjects with higher arrest ratios (self-reported arrests to self-reported crimes) also reported higher risk perceptions, indicating that active offenders may learn from their offending experience. In turn, those believing that they face higher risks in lawbreaking have been found to commit fewer crimes (Nagin, 1999).

Public awareness of sanctions is also critical to their value as a deterrent. People will not be deterred by a sanction about which they have little knowledge. The Canadian Sentencing Commission's (1987) research suggests a lack of awareness of sentencing laws and practices in Canada, especially in relation to MMS. The Latimer case illustrates this point as the jury was unaware that murder in this country carries a mandatory life sentence.

Date modified: