Hi Sleuths, we are saying trigger warning on this one. It is old timey AF but also, he was a twisted person. This may be the first documented serial killer.
The Devil in the White City by Erik Larson
https://en.wikipedia.org/wiki/H._H._Holmes
http://hdl.loc.gov/loc.rbc/General.22698.1
https://www.legendsofamerica.com/h-h-holmes/