After reading Nine Corrupt Pillars of Classical Greece, I decided to look for a few more publications of Lord Acton’s essay “Human Sacrifice”. I managed to find one at the Internet Archive, in addition to the original work.
There are a few related online essays on the subject, including Human sacrifice in Ancient Rome by M. Horatius Piscinus, and a quick survey of 25 ancient cultures who were into cultic murder, mainly to appease their gods (read: demons.)