Sequential killers vs. serial killers

Context:

I was watching a period TV series (The Artful Detective) which is set in Toronto, Canada around 1900 to about 1910 or so. The lead detective is a member of the Toronto Constabulary. It features any number of technological anachronisms that are fun to pick out.

In the episode I was watching they referred to a series of murders as "sequential murders" rather than use the more commonly heard modern term "serial killer". This was a necessity as the term "serial killer" did not exist prior to the early 1970s when an FBI agent coined the phrase.


Question:

Was "sequential killer" ever a standard term? Prior to the coining of "serial killer" those killers would have been termed "mass murderers". Since the series takes historical liberties I'm wondering if "sequential killer" is an invention of the TV writers.

Packard said:

I'm wondering if "sequential killer" is an invention of the TV writers.

What you write under "Context" does not say the writers used "sequential killer."

"Sequential murders" sounds like part of an ordinary description of what was happening, not a coined phrase.

srk said:

What you write under "Context" does not say the writers used "sequential killer."

"Sequential murders" sounds like part of an ordinary description of what was happening, not a coined phrase.

They were using it as a label (from an online script):

You think this could be the work of a sequential killer? We do have two confirmed murders and a thumb - suggesting a third.

Read more: The Murdoch Mysteries (2004) s08e18 Episode Script | SS

And:

Ritualistic perhaps, another mark of a sequential killer.

Read more: The Murdoch Mysteries (2004) s08e18 Episode Script | SS

As an aside they also reference "fingerprints" as "fingermarks" or "thumbmarks". Historically fingerprinting was in use about that time.

And the detective gets to use his stun gun called " It's a weaponized capacitor! It delivers an electrical shock by way of these darts."

Read more: The Murdoch Mysteries (2004) s08e18 Episode Script | SS

Doubtless this is historically incorrect.