Analysts often examine hot spots by use of geography alone. This can often be a useful starting point, but to reduce or eliminate the hot spot you must look deeper to understand why it is a hot spot. We focus on developing an understanding of the processes that create hot spots. Later, in Steps 23 and 55, we examine how to analyze and map hot spots without letting your mapping software call the shots. As we have seen in previous steps, small areas - places - are critical to understanding many problems and developing effective responses. We, therefore, focus on hot spot places in this step. In later steps we will build on this idea to examine hot spot streets and areas.

There are three kinds of hot spot places, each with its own underlying causal mechanisms:

• Crime generators are places to which large numbers of people are attracted for reasons unrelated to criminal motivation. Providing large numbers of opportunities for offenders and targets to come together in time and place produces crime or disorder. Examples of generators include shopping areas, transportation hubs, festivals, and sporting events. The large number of crime or disorder events is due principally to the large number of place users and targets.
• Crime attractors are places affording many criminal opportunities that are well known to offenders. People with criminal motivation are drawn to such locales. In the short run, offenders may come from outside the area, but over longer time periods, and under some circumstances, offenders may relocate to these areas. Prostitution and drug areas are examples. Some entertainment spots are also well known for allowing deviant activity. Such places might start off being known only to locals, but as their reputation spreads increasing numbers of offenders are drawn in, thus increasing the number of crime and disorder events.
• Crime enablers occur when there is little regulation of behavior at places: rules of conduct are absent or are not enforced. The removal of a parking lot attendant, for example, allows people to loiter in the parking area. This results in an increase in thefts from vehicles. This is an example of an abrupt change in place management. Sometimes place management erodes slowly over time, leading to problem growth. Crime enablers also occur with the erosion of guardianship and handling. For example, if parents attend a play area with their children they simultaneously protect the children (guardianship) and keep their children from misbehaving (handling). If parenting styles slowly change so that the children are increasingly left to themselves, their risk of victimization and of becoming offenders can increase.

Patricia and Paul Brantingham suggest that areas can be crime neutral, i.e., they attract neither offenders nor targets, and controls on behaviors are adequate. These areas tend to have relatively few crimes, and the crimes tend to be relatively unpatterned. For this reason, crime-neutral areas seldom draw police attention. Though they seldom require crime analysis, they are important because they provide a useful comparison to the other types of areas. Comparing crime-neutral areas, for example, to a hot spot can help identify the differences that create the troubles in the crime generator, crime attractor, or crime enabler. Case-control studies (Step 32) are useful for this purpose.

In summary, when a crime or disorder hot spot becomes a greater problem it is generally because the number of targets has increased, the number of offenders taking advantage of the hot spot have increased, or because the level of control being exercised at the site declined. Often, all three are at work. Shoppers might increase in an area, for example, due to new roads. This might lead to increased thefts as offenders take advantage of the new theft opportunities. Successful offending might attract new offenders. Increased offending might cause the number of shoppers to decline. This removes guardianship (shoppers). But it has another effect. It could reduce place management as the resources of the businesses decline. So, a problem that started out as a crime generator evolved into a crime attractor and then into a crime enabler.

We can compare numbers and rates to diagnose which of these mechanisms may be operating. Dividing the crimes in question by the number of possible crime targets creates rates (Step 27). This is often expressed as the number of crimes per 100 targets available. So, for example, if a parking lot has 15 car break-ins during a year, and the lot contains 150 spaces and operates at near capacity, its break-in rate is 15/150 or .1. This translates to 10 break-ins per space per year. Note that this analysis is only useful if the lot is operating near capacity. If only 50 spaces are used on most days, then the rate is three times as high (15/50=.3 or 30 break-ins per vehicle per year).

Table 1 illustrates the differences in ranking the importance of hot spots depending on whether numbers or rates are used. Place A is the "hottest" spot in terms of numbers but second in terms of rates, and place C goes from third hottest to first when one switches from numbers to rates.

Let's look at how hot spot mechanisms generate indicative combinations of numbers and rates. Crime generators have many crimes, but as their number of targets is high, they have low crime rates (Place B in Table 1). Crime attractors also have many crimes, but as they have relatively few targets, their crime rates are high (Place A). Crime enablers, with their weakened behavior controls, tend to be unattractive to targets. However, those few available targets have high risks. So a place with relatively few crimes but a high crime rate suggests a crime enabler (Place C). Finally, the number of crimes at crime-neutral locations will be low, so even if the number of targets is not particularly great, their crime rate will also be low (Place D). Table 2 summarizes these relationships.

The rankings of numbers and rates are relative, so this process is useful for comparison purposes. And there may be multiple mechanisms operating. Low behavioral controls (enabler) may also attract offenders (attractor), for example. Nevertheless, such comparisons provide an early indicator of how to proceed and establish hypotheses for later examination (see Step 20). Such analysis will help suggest the types of responses that could be effective. This is summarized in Table 3.

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