enough or the desire sufficient, he may kill. Whether he plans the
method or deliberates upon the act can make no difference. He is
prompted by the instinct, and the reflection simply means the
consideration of reasons for and against, or the reaching of
inhibitions. If he acts, it is one of the primal emotions that causes
the act. He is the "machine" through which certain emotions find their
path and do their work. Infinite are the causes and circumstances that
give rise to an emotion strong enough to take human life.

Killings which result from a sudden passion are easily understood.
Everyone has been overwhelmed by rage, where reason and judgment and all
acquired restraints are entirely submerged. The primitive man with his
primitive emotion reasserts himself. It is mainly accident or the lack
of some particular circumstance that prevents a murder. Of course some
people are overwhelmed more easily than others. Some natures are less
stable, some nervous systems less perfect, and the built up barriers are
weaker. The whole result of stimuli is determined by the strength of the
feeling acting upon the machine. Such a person is not ordinarily
dangerous to the community. The act itself would generally assure that
it could never happen again. Some killings, however, are more
deliberate. They are preceded by a settled hatred which preys upon the
mind and fights against the preventive influences that training and
habit have formed. Under a certain combination of circumstances these
restrictions are swept aside and the emotions have their way.

There are, of course, certain broad classifications of homicides. A
considerable number, perhaps more than any other, come through the
commission of robbery, burglary and larceny. In the midst of the act the
offender is caught, and kills in an effort to escape. These murders fall
under the heading of property crimes; the cause is the same, and the