The murderer is afraid of being caught by the police forces which can discover the body of his victim.
It is not just a modern fear, but the pattern of the guilty conscience. The hidden corpse is the core of the murder and not the wrongdoing which produced it. When a wrongdoing has not a concrete result like the corpse, the guilty conscience that is responsible for a great mistake against other person makes an imaginary one.
The imaginary corpse is nothing particularly, but only an annoying image of our victims which unashamedly occupied a place in the inner space of our consciousness. Therefore, the remorse for those victims can be easily transformed into a feeling of hate. The murderer often hates the corpse of his victim, too.
Since the wrongdoing is not the object of the guilty conscience, its author can absolve himself very fast even through shallow explanations. The deeper hate for his victim helps him in this effort. The victims cannot bother him too much and it doesn’t seem to deserve more than a shallow explanation for their repression.
For someone’s guilty conscience, the fear of being caught by the police is that of meeting persons who will be able to invade his consciousness in its deepest area. For this reason, the wrongdoer feels himself safer when he keeps other people far from him. The loneliness defends him for not being grabbed by other people. Like the policemen, they will grab him even if they have good intentions, because there is a common and egoistical satisfaction to love or hate a person who is seized once her weakness is known.