People used to use the term "psychopath." Although dictionaries often give slightly different definitions for these two terms, there does not seem to be a substantive technical difference. The term psychopath entered the vernacular in the 60s with the release of Alfred Hitchcock's movie, Psycho, a name that strikes me as having a more compelling ring than Socio.
This cultural/psychological difference between the terms helps to explain why the preferred term today is sociopath. For some reason, technical professionals don't want everyone to assume that every sociopath is necessarily a cold blooded killer. The issue with this disorder, however, is that the person so afflicted lacks any compassion or moral conscience. (Presumably, a person that is only somewhat lacking in these virtues is not labeled a sociopath.)
It seems to me that the crux of the issue is at least as much spiritual as psychological. Sociopathy is associated with a general lack of virtue. A sociopath is someone who is typically highly narcissistic, pretty unconcerned about anyone other than himself or herself. Indeed, the sort of person who might be a serious concern to law enforcement might also be labeled a malignant narcissist.
There are many issues connected with this problem. In a society particularly afflicted with the vice of a sense of personal entitlement (rather than a sense of obligation to pull one's own weight, in addition to doing what one can to help those who cannot help themselves) people are much less likely to spot those who are malignant narcissists, because their behavior will not stick out like a sore thumb, except perhaps in competitive situations. It's even possible for a malignant narcissist to win a national election, and for people to not recognize the problems until many years later.
So it should not be surprising that the incidence of violent outbursts by sociopaths is becoming more frequent.
Unfortunately, our post-modern society is ill-equipped to recognize the true nature of the problem, and even less well equipped to do anything productive about it.