In the 1900s if you killed a person it was a huge, town-wide dealio.
Now, in some places, there are multiple murders, rapes, muggings and more, a day! When did this become part of living?- Part of everyday life? Why and how did this come to be?
There are many reasons why people do the things they do, whether it's impulse, not being mentally stable, or just because of a traumatic event or maybe it was an accident. The majority of the time, major crimes are committed by unstable people. Possible motives are money, threat, and satisfaction. Everyone's head works differently, so you never can see anything coming until it's already done.
We are all truly crazy in one way or another.