Beyond the actual murder victims, there are a host of secondary victims who suffer from the crimes of serial killers (Fox & Levin, 1996b; Holmes & De Burger, 1988; Ressler et al., 1988). Family and friends experience the grief, loss, and financial strain associated with the death of a loved one, and they are often subjected to “repeat victimization” by the press, police, and courts. Treatment programs are available for offenders, but usually there is no provision for psychological counselling for victims’ families. In response to these issues, self-help groups and advocacy agencies such as Parents of Murdered Children, the Adam Walsh Child Resource Center, and Victims of Violence International have been formed (Sullivan, 1995).

Society is also victimized by these predators through the resulting fear and suspicion they cause (Fowler, 1990). Increased mistrust of strangers, fear of public spaces, and reluctance to help others all contribute towards the breakdown of community. Additionally, the economic losses associated with cases of serial murder are high; investigation expenditures, court costs and legal fees, and long-term incarceration expenses add up to millions of dollars (Victims of Violence Society, 1990). The psychological and fiscal impact of serial murder spreads far beyond the small number of actual homicide victims.

2.2 Child Murder

Child murder is a matter of great concern to society. Most murders of children are committed by family members and stranger child homicide is rare. Still, when this type of crime does occur, the impact on a community is tremendous. It has been suggested that some serial murderers target children because they represent the future. These offenders are extracting revenge from a society they feel has wronged them. Adults, however, are the most common victims of serial killers (Hickey, 1997). The U.S. Office of Juvenile Justice and Delinquency Prevention (OJJDP) estimates that annually there are one to two stranger abductions per million population, with teenagers (14 to 17 years of age) at highest risk (Allen-Hagen, 1989; see also Lau, 1989); this figure does not seem to be increasing. Serial murder cases with child victims are more likely to involve a family member or acquaintance as the offender.

Child molesters may be either situational or preferential (Lanning, 1995). Situational offenders do not prefer children, but will victimize them

— and any other group — that opportunity presents. Preferential offenders, often referred to as pedophiles, do possess a sexual preference for children, and will typically develop skills in identifying and targeting vulnerable victims. Some pedophiles can watch a group of children and often know which ones are from dysfunctional families (Lanning, 1995). Child molesters tend to be nomadic as they often have to move when their presence is

© 2000 by CRC Press LLC

found out. Many pedophiles are predators who repeatedly commit crimes, but only a few are killers.

Extensive study of child murder and its geography has been done in both Great Britain and the U.S. The CATCHEM database contains information since January 1, 1960, on all child sexual homicides in the U.K. (Burton, 1998; Copson, 1993). With over 3000 cases, the system analyzes murder and offender data for investigative prediction purposes (see below). It is maintained by the Derbyshire Constabulary, and administered by Detective Inspector Chuck Burton who has discovered several interesting findings in the data. The clearance rate for child sexual homicides where the victim was transported was less than half that for crimes with no transportation. The offender’s vehicle is often the murder scene in cases of victim transportation. The more locations used in the murder (i.e., separate encounter, attack, murder, or body dump sites), the more geographically complex the crime, and the lower the clearance rate.

In cases where the victim was not transported by vehicle (n = 190), 98% of the victim’s bodies were deposited within 50 yards of a footpath, and all were found within 100 yards. While concealment appeared to be intended in 46% of these cases, only 5% of the time was the body buried, as opposed to 17% of the cases where it was placed in water. The body was found within a half mile of where the victim was last seen in 91% of the cases, and within one mile 97% of the time.

In child homicides involving victim transportation by vehicle (n = 89), 88% of the victim’s bodies were deposited within 50 yards, 97% within 100 yards, and all within 150 yards of a road or track affording vehicular access. The body was left outdoors 94% of the time. While concealment appeared to be intended in 57% of the cases, only 12% of the time was the body buried, as opposed to 20% of the cases where it was placed in water.

Hanfland, Keppel, and Weis (1997) conducted a study of child abduction murders in the U.S. There are approximately 100 such incidents annually, comprising only 0.5% of all murders. The project analyzed 777 case investigations, representing 562 child victims and 419 killers. Of these, 138 cases were part of 55 series. The typical victim was female, mean age of 11 years, and sexual assault was the primary motivation. Stranger offenders were involved in 53%, friend or acquaintance in 39%, and family member or intimate in 9% of the cases. The older the victim, the greater the likelihood the murderer was a stranger.

The typical offender was 27 years of age, male, and unmarried, though only 17% lived alone. About 50% were unemployed and 16% were transient. The majority had criminal records, 60% with previous violent crimes. More than half of the murderers had committed prior offences against children; this increased to 76% for serial offenders. A similar modus operandi was

© 2000 by CRC Press LLC

present in two-thirds of the offenders’ prior crimes. Police had contact with the killer before he became a prime suspect in about one third of the murders, usually within 24 hours of the crime. Investigative red herrings are not uncommon in child homicides, and the study found they were encountered in 38% of the cases. Despite perceptions to the contrary, the media helped more often than it hindered an investigation.

In child abduction murder cases, the victim was killed in less than 1 hour in 44%, 3 hours in 74%, and 24 hours in 91% of the cases. Only 42% of the victims were still alive at the time they were reported missing. The majority were opportunistic (57%), and only a few were specifically targeted (13%). Serial offenders selected male victims more often than nonserial offenders (38 vs. 22%). Most of the serial crimes involved stranger offenders (80%).

Hanfland et al. (1997) geographically analyzed child murder, dissecting the incidents into victim encounter, murder, and body recovery sites. The typical child abduction murder scenario involves a victim encountered in an urban area near their home, transported to a rural area, killed, and then dumped near the murder site. Confirming the CATCHEM research, this study found murders involving multiple locations are difficult to solve; the more sites, the lower the clearance rate.

The encounter site is usually close to both the victim’s residence (less than 200 feet in 33%, and less than 0.25 miles in 58% of the cases) and last known location (less than 200 feet in 65% of the cases). If the encounter site was unknown in a murder investigation (17% of the time), the clearance rate dropped to 40% below the mean; if known, it rose to 13% above the mean. This indicates the importance of thorough neighbourhood canvasses and area searches. The killer was in the area of the encounter site because he belonged there two thirds of the time, underlining the need for police to not only ask what was unusual, but also what was normal during their canvasses. In 29% of the cases, the offender lived in the neighbourhood, within 200 feet of the victim encounter site in 18%, and within 0.25 miles in 35% of the crimes.

Next to the body recovery site, the murder scene possesses the most physical evidence (see also Lowman & Fraser, 1995); unfortunately, in multiple location crimes, it is the site most often unknown (23%). Distance from murder site to body recovery site was less than 200 feet 72% of the time. Distance from the murder site to the encounter site was less than 200 feet in 31%, and less than 0.25 miles in 47% of the cases.

The body recovery site contains the most physical evidence; fortunately, it is almost always located, at least in those cases known to police. Concealment of the corpse was more likely in child abduction murders (52%) than in murder generally (14%). A child’s body can be very difficult to find because of its small size. For example, the body of a child 4 feet in height requires

© 2000 by CRC Press LLC

only about one-third the volume of a 6-foot-tall adult. Consequently, searchers have to be especially diligent when looking for young children.

Some offenders returned to the body dump site (22%), and some left town following the murder (21%). The killer occasionally kept the victim longer than necessary (15%), but this was usually for less than a day. In these situations, the body was stored in the offender’s residence (50%), vehicle (28%), or other easily accessible location (22%). Rarely (5%) was the victim’s body actually recovered from the killer’s home. The choice of the body dump site was specific in 37%, random in 37%, and forced by circumstances in 14% of the murders. The victim was found in his or her own home in 4% of the cases; younger victims were more likely to be dumped closer to their home. Approximately 63% of the time, the body was located more than 1.5 miles from the victim’s residence. Evidence discarded by the murderer was recovered in 21% of the cases. More often than not (59%), it was recovered within 1 mile of the body dump site, and half the time it was found along the roadway travelled by the killer.

2.3 Murder and Distance

In a Washington State study of single-victim single-offender murders from 1981 to 1986 (n = 967, 74% cleared), Keppel and Weis (1994) found the more information known regarding times and locations of the crimes, the greater the likelihood the case will be solved. Crime locations provide evidence and witnesses; time of offence allows suspect alibis to be verified or refuted. Together, they permit investigators to establish if the victim and a suspect were in the same area at the same time.

Their study broke murder down into five potential different locations: (1) victim last seen site; (2) initial contact site; (3) initial assault site; (4) murder site; and (5) body recovery site. Police investigators are most likely to know the location of body recovery, followed in order by the murder, victim last seen, initial assault, and initial contact sites. This information influences case clearance in two ways. First, the more crime sites known, the greater the chance the case will be solved. If at least four of the five potential locations are known to police, the clearance rate is 85%; otherwise, it is only 14%. Second, the study found higher clearances associated with those murders characterized by shorter distances between crime sites, particularly from where the victim was last seen to body recovery. The clearance rate is 86% if this distance is less than 200 feet, dropping to 50% if it is greater. Longer distances impede and delay finding all crime locations, and therefore all available evidence.

Keppel and Weiss note that 24 hours appears to be a critical time threshold. As time elapses, evidence deteriorates and witnesses’ memories fade.

© 2000 by CRC Press LLC

While a murder suspect was in custody within 24 hours in 66% of the cases, the chances of the crime being solved dropped significantly if no one was arrested by 48 hours. The study found more cases cleared where the time between locations was less than 24 hours, with an average decrease of 30% in the solution rate otherwise. If the time between when a victim was last seen and when their body was recovered was less than 24 hours, the clearance rate was 82%; otherwise, it dropped to 42%.

Dramatic differences are found by combining time and distance effects. If there are 24 hours or less between the time a victim is last seen and when their body is recovered, and if the distance between these sites is less than 200 feet, the clearance rate rises to 86%. If the time is greater than one month, and the distance more than 1.5 miles, the clearance rate drops to 4%. Offenders may intentionally separate the locations associated to a murder to delay body recovery, facilitate evidence destruction, involve different police jurisdictions, and complicate the investigation.

© 2000 by CRC Press LLC

Serial murder is rare, but serial crime is not. While this book is primarily concerned with serial killers, rapists, and arsonists, many bank robbers, burglars, auto thieves, shoplifters, and con artists are also serial offenders. Several studies have shown that the distribution of offending frequency rates, lambda (λ), is highly skewed with some criminals possessing λ values in the range of 10 to 50 times that of others (Canela-Cacho, Blumstein, & Cohen, 1997; Marvell & Moody, 1998). This implies a high degree of serial criminality. For example, if we make the modest assumption that 10% of offenders demonstrate a λ value 10 times that of the other 90%, then this results in over 50% of all crimes being the responsibility of only 10% of offenders. One study of paraphiliacs (n = 411, mean duration of deviant arousal = 12 years) found, on average, 581 attempted and 533 completed sex offences, and 336 victims per offender (Abel, Mittelman, & Becker, 1985). But these averages are misleading because 70% of the offences were actually committed by only 5% of the offenders.

The very nature of a skewed λ distribution means that, while most criminals are not serial in nature, most crime is. Similarly, Hare (1993) notes that approximately 20% of prison inmates are psychopaths — versus only about 1% of the general population — and these individuals are responsible for more than half of all serious crime. In a study of fugitive migration, for example, Rossmo (1987) found that Canadian criminal fugitives had a mean of 15 previous charges and 10 previous convictions.

It has been suggested the difficulty in determining who is a serial predator could be addressed by replacing crime count with a psychodynamic assessment of a criminal’s propensity to re-offend (Kocsis & Irwin, 1998). Compulsive criminal fantasies appear to be fed by a distinctive internal drive mechanism, involving the elements of psychopathy, narcissism, sadism, paraphilia, fantasy, compulsiveness, and dissociation. For example, Prentky, Burgess, Rokous, Lee, Hartman, Ressler, & Douglas (1989) found that serial

© 2000 by CRC Press LLC

sexual murderers were much more likely than single sexual murderers to have acted out conscious fantasies (86 versus 23%).

A stranger victim is one mark of a serial offender. Kocsis and Irwin (1998) suggest the following additional indicators of serial crime:

•Murder: postmortem mutilation or cannibalism, stylized or “dramatic” positioning of the corpse, sexual assault, necrophilia, overkill, torture, and souvenir collection.

•Rape: stylized verbal scripts demanded from the victim, sadistic or violent behaviour, paraphilic activities, offender’s inability to penetrate the victim or to climax, and souvenir collection.

•Arson: destruction of property in addition to fire damage, sexual activity at the crime scene, the presence of signature (e.g., graffiti, fecal matter or urine, token object), and stylized behaviour in the fire setting.

Alston (1994) differentiated between series types and classified them into five different patterns. A class I series (the most common) is the traditional case of a single offender with multiple victims. A class II series involves two offenders and multiple victims. Class III, IV, and V series comprise several offenders attacking multiple victims in different partnership combinations (e.g., Smith commits some of his crimes with Jones, others with Anderson, and still others alone). Alston notes that higher order types are unstable and often break down into class I or class II series.

Serial murder, rape, and arson cases comprise the bulk of the demand for geographic profiling services. How similar, at least geographically, are these different types of crime? Warren et al. (1995) observed variations in the spatial patterns of serial rapists and arsonists, noting that the latter were more likely to reside within the perimeters of their hunting areas. They suggest “geographical patterns of serial offenses may be crime specific, and that patterns that are characteristic of some types of serial crime may not be characteristic of others” (p. 219).

While this observation is likely correct to a point, it also appears that the similarities are stronger than the differences. Research on the geography of serial predators has demonstrated many commonalities,14 and operational experience has helped confirm these findings. Parallels in spatial behaviour appear to be the product of common underlying human processes. Taylor (1977) makes the argument that “there are no patterns; there are only processes” (p. 134).

14 This research has studied serial murder (Hickey, 1997; Holmes & DeBurger, 1988; Rossmo, 1995a), serial rape (Alston, 1994; Canter & Larkin, 1993; LeBeau, 1987a, 1987b, 1992; Warren, Reboussin, & Hazelwood, 1995), and serial arson (Icove & Crisman, 1975; Sapp, Huff, Gary, Icove, & Horbert, 1994).

© 2000 by CRC Press LLC