After locating a new file,I continue with The Ultimate Evil by Maury Terry...

[.... Looking back, I realize the indications were present all along. I never ignored them, but did keep them at a safe distance those first four months—slightly out of focus on the horizon. Publicly, I'd hold them sequestered for two years. The reason I did so wasn't complex: the idea of satanic cult involvement in the .44 killings was initially too bizarre for me to even want to consider.

Such groups certainly existed. There was ample documentation from across the country. But my entire thrust was aimed at uncovering the presence of a single accomplice. Frankly, I didn't want to confront the implications, or face the consequences, of still more conspirators. As a result, I kept steering away from the signs. But inevitably, I was pulled back into the web. And after a time, I came to accept the unacceptable.

The path of the old Croton Aqueduct in Yonkers passes between the rear of the Carr home and Berkowitz's apartment building. At one time, the aqueduct—an underground pipeline approximately eight feet in diameter—carried drinking water from the Catskill Mountains watershed region to New York City via the Croton Reservoir in northern Westchester County. It was now obsolete. Above it, at ground level, one could walk a wide path which snaked for miles through numerous Westchester communities.

In the early 1900s, some Yonkers residents dug tunnels from nearby basements and managed to tap into the water supply. Although most were later sealed, apparently some of the old tunnels still existed, offering access to the now-empty pipe from the cellars of a handful of aging homes in the area. Also, at select locations on the surface, entrance to the subterranean passage could be gained through hidden, and long-forgotten maintenance portals.

Once inside the aqueduct itself, it was possible to walk for at least several miles beneath the ground. The pipe was damp and musty, groundwater seeped through the rust at points, and vision was impossible without a flashlight or candles.

Behind the Carr home, the aqueduct path cut through a wooded area. A mile to the north, it traveled through the lower reaches of Untermyer Park—a sprawling, formerly lavish estate that had fallen into considerable disrepair. Once owned by Samuel Tilden, a U.S. presidential candidate who lost the 1876 election to Rutherford B. Hayes, the land was purchased by wealthy attorney Samuel Untermyer in 1903. Untermyer, whom a British magazine labeled a satanist, imported stone and statuary from England to embellish the landscape. Other researchers stated that Untermyer had belonged to the Golden Dawn society—a nineteenth-century British- based ritual-magic organization that had claimed infamous black-magician Aleister Crowley as a member, Both the Golden Dawn and Crowley would later become relevant in the investigation....]
https://exploringrealhistory.blogspot.com/2019/06/part-5-ultimate-evilthe-process-into.html