Target hardening is probably the most popular and most recognisable form of situational crime prevention. It encompasses security devices such as locks, fences, barriers, special glazing, armour and alarms. At its most basic it may simply mean shutting the windows of empty buildings. The rationale behind these measures is that spontaneous offenders will be put off and determined offenders held up, thus increasing their likelihood of being caught. There has been increasing research in recent years illustrating the benefits of target hardening methods.
Probably one of the more famous examples is Mayhew et al.'s (1976) research into the fitting of steering locks in cars in West Germany and the UK, a tactic that led to a decline in the number of thefts of cars. More recently, research by Mayhew et al. (1993) has found that offenders are less likely to gain entrance to a household with three or more security devices than a household with none. Similarly, Bennett and Wright (1984) have found, following interviews with convicted burglars, that some would be deterred by special security locks. In a study of post office robberies, Ekblom (1987) was able to show that the introduction of protective screens reduce incidences, just as Austin (1988) found for retail banking and finance outlets. Jacques (1994) has illustrated the benefits of shutters in preventing ram raids, while Butler (1994) has shown that certain security devices such as electronic article surveillance systems deter shoplifters from offending.
There are a number of criticisms of target hardening. One of the most salient is the issue of deflection, which will be explored in greater depth later. However, there is also a concern that the use of target hardening measures may, in general, increase the public's fear of crime and in businesses may, consequently, affect staff morale. There is also a danger of pursuing these strategies at the expense of others, leading to a spiralling fortress mentality.