I am not sure what section to post this piece in and, although it relates mainly to the USA, it has relevance to the U.K.-Ron in Tasmania

The origins of "serial" terminology as applied to crime and violence are much debated, but the concept probably emerged in criminological writing during the 1960s. This was the period of my teens and twenties: I was 15 in 1960 and 25 in 1970. I belong to the sixties generation. Many shifts occurred in that decade, the first decade of my membership in the Baha’i Faith. But whoever first coined the use of the word ‘serial’, until the early 1980s, it was largely confined in its use to a handful of criminologists and psychologists who studied multiple homicide.

As recently as 1982, just three decades ago, a book on Jack the Ripper or Ted Bundy was advertised as a case study of "mass murder." Matters changed very rapidly over the next two years, 1982 to 1984, as the concept of serial murder entered popular thought. One pivotal event was the hearings before a US Senate committee in the summer of 1983. Those hearings dealt with "patterns of murders committed by one person in large numbers with no apparent rhyme, reason or motivation." Between 1983 and 1985, serial murder became one of the most intensely debated issues in the media, both in serious news outlets and popular culture, to the extent that the USA experienced what could be described as a general panic. That panic has not ended. -Ron Price with thanks to Philip Jenkins, “Catch Me Before I Kill More: Seriality as Modern Monstrosity,” Cultural Analysis, Volume 3, 2002.

Serial murder has mythological connotations.
Uniquely dangerous predatory villains against
whom no counter-measures were too extreme.
By the 1980s our concepts of science & the
supernatural no longer accommodated a literal
belief in archaic vampires and werewolves, but
the media metaphorically compared these serial
criminals to those traditional monsters. These
newly re-imagined serial killers could be cited
quite freely as undoubtedly authentic beings
whose existence was vouchsafed by social and
behavioral science and who fulfilled mythical
roles of the supernatural night-prowlers of old.
The fact of uncontrollable repetition, absolute
lack of self-control, that made serial killers less
than human and denoted them as monsters---
and as all this was happening I moved through
my middle age and into late adulthood: yes, the
world was a dangerous place for the age was the
darkest hours before the dawn of a new age, an
age emerging from the chaos of these epochs, a
time, an end of history, a tempest unpredictable
in its course and unprecedented in its magnitude.

Ron Price