In all of the “missing wife” cases I have investigated, it became clear to me that “getting away with murder” was an essential force, but not the only force, driving these killers. One might assume that every killer, every criminal of any sort, wants to get away with his crime. But the majority of domestic homicides don’t happen that way. Most are not planned, not carefully calculated and covered up. In fact, in most intimate partner murders, there is no real attempt to "get away with murder." Many men who kill their wives or partners in a violent argument, the heat of the moment, or in an act fueled party by drugs or alcohol, the killer actually experiences considerable remorse. One recent study suggests that up to 40% of men either committed suicide afterwards, tried to do so, or thought about it. Many other wife killers simply run from the crime scene.
Eraser killers aren't like that because they are most likely "calm" (in the kind of calm that only psychopaths can exhibit) as they commit the murder. Scientific studies of psychopaths indicate that they experience little or no fear in resonse to situations or images that would make most of us very fearful.
The meticulous planning and supreme self-control exhibited both before and after these crimes seemed to be a significant aspect of these men’s characters, far beyond the murderous aspect of their personalities. The expertise at lying and manipulation needed to live a double life is indicative of a high degree of Machiavellianism. While political scientists and others sometimes use this term, psychologists have developed a formal category and accompanying tests and measures for people whose psychological makeup ranks high in Machiavellian traits.
Other malignant personality traits seemed to be involved as well: cold-blooded psychopathic tendencies and extreme degrees of narcissism. But there was something else curious about these men’s characters. Erasing their victims appeared to be not just a means to an end but and end in itself. Once they made the decision to kill, they began purging all trace that the victim ever existed from their lives. Many began getting rid of the woman’s possessions within days of her disappearance, pulling up stakes, changing their lifestyles dramatically. Some immediately replaced their missing wives or girlfriends with other women—sometimes with look-alikes for the disappeared. And, most shockingly, some later attempted to get away with murder again, erasing another wife or girlfriend, sometimes in exactly the same manner as their first crime.