Sam killed his early victims in different precincts (Ressler & Shachtman, 1992). Serial rape is just as susceptible to linkage blindness, but serial arson is less so due to the limited geographic range of the typical arsonist.

Several other investigative difficulties exist that complicate efforts to link crimes and apprehend serial killers and violent sex offenders (Egger, 1990, 1998; Holmes & De Burger, 1988; James, 1991; O’Reilly-Fleming, 1992). These problems include:

•The intense public fear, media interest, and political pressure surrounding these cases;

•Police inexperience19 with serial murder cases, including an unwillingness to acknowledge the situation and commit sufficient resources, ignorance of appropriate investigative strategies, and overlooking victimological information;

•The complexity of personnel and coordination logistics, especially when multiple jurisdictions and agencies are involved. In the Yorkshire Ripper case, for example, 250 full-time detectives were assigned for over a three-year period (Doney, 1990);

•Offender learning and improvement from “practice;”

•Copy cat crimes; and

•False confessions from unbalanced people attracted by the notorious publicity.

In a comparison of solved (n = 399) and unsolved (n = 75) serial murder cases, Mott (1999) correctly hypothesized the former group would be characterized by higher killing rates, lower victim vulnerability, and indoor body disposals. Contrary to her expectations, however, offender mobility and multiple crime sites were also related positively to crime solution, though she cautions these results may be data artifacts. Discriminant analysis correctly classified 75.2% of the cases.

4.2 Police Strategies

For heaven’s sake catch me Before I kill more. I cannot control myself.

—Message written in lipstick on the living room wall of Frances Brown, victim of serial murderer William Heirens; Kennedy, 1991, p. 38

19 Many countries, including Britain, Canada, and the U.S., are now attempting to pool investigative expertise in “low volume crimes.” Perhaps the current record is held by Captain Piet Byleveld of the South African Police Service in Johannesburg, who has investigated six serial murder cases during his career.

© 2000 by CRC Press LLC