To give some insight into the scale of the problem posed by the serial killer, in the United States can be gained from examining the statistics for just one year. In 1989 (the last year for which detailed figures are available) there were 21,500 recorded homicides, of which some 5,000 are unsolved. Unofficial sources believe that as many as a hundred serial killers may be at large at any given time. Add to this the number of known victims of serial killers, then between 3,500 and 5,000 people are killed by serial murderers every year. (Lane and Gregg 3)
These numerous multiple murders, often without consequence and justice, have shocked civilized society with incomprehensible acts of inhumanity. Horrific amounts of body counts and volumes of spilt blood accompany the discovery of each new serial killer. The indescribable events associated with each murder leave such unanswered questions as: what deviations lurk in the mind of a serial killer, what provokes an individual to commit such hideous acts, and what can be done to reduce these inconceivable murders?
There are a set of variable elements, which distinguish the "serial" murder from the single-incident ("normal") murder, the "mass" murder, and the "spree" murder. The "mass" murder can be defined as an act in which a single assailant kills a number of people during a short period of time in roughly the same geographical location. The "spree" murder can be defined as a multiple number of killings, which take place during a short period of time, hours or days. The "serial" murder exhibits five distinct sets of characteristics, which help distinguish it from the "mass" murder and "spree" murder. First, the killings are repetitive ("serial") and often escalate over a period of time, sometimes years, which will continue until the killer is taken into custody, dies, or himself is killed. Second, the killings, like "normal"