Read Suspected Gilgo Beach Serial Killer's 'Planning Document': 'Hit Harder, Use Heavy Rope, More Sleep = More Playtime'

On Thursday, Heuermann was charged with the murders of two additional women -- Jessica Taylor and Sandra Costilla -- following earlier charges in the deaths of Amber Lynn Costello, Melissa Barthelemy, Megan Waterman and Maureen Brainard-Barnes.

As part of the superseding bail application, the Suffolk County District Attorney's Office detailed the digital evidence allegedly recovered after numerous search warrants were executed on Heuermann's devices.

Warning: Graphic details below.

"An analysis of these devices has revealed Heuermann's significant collection of violent, bondage, and torture pornography, currently dating back to 1994," reads the docs. "The pornographic images accessed by Heuermann include, but are not limited to, breast mutilation, vaginal torture, sex substitution (i.e., penetration with an object), the sexualization of decapitated women, bondage, and whipping, which notably and largely coincide with how the remains of Sandra Costilla, Jessica Taylor, and Valerie Mack were discovered."

A Word Document believed to have been deleted by Heuermann was also discovered, one which investigators believe "to be a 'planning document' utilized by Heuermann to methodically blueprint and 'plan out' his "kills."

Appearing on Good Morning America on Friday, DA Raymond Tierney said, "We allege that the planning document shows his motivations, his meticulous planning and his clear intent to murder those six victims." He added, "It's our allegation that there was a plan to abduct these women and keep them for a period of time."

The doc was divided with subheads for "PROBLEMS," which investigators believe "to be a guide on issues to avoid apprehension, "SUPPLIES, "DS" or "Dump Sires," and "TRG," which they believe is a reference to "target or victim."

Among the "Problems" mentioned are blood stains, finger prints, witnesses, police stops and DNA. Supplies, meanwhile, include lye/acid, cutting tools, burn can, tarps and hair nets. Dump sites include dumpsters, while authorities believe the phrase "small is good" under "TRG" referred to the physical size of the alleged victims.

Other categories on the doc include "PRE-PREP," "PREP" and "POST-EVENT," which authorities believe lay out plans before, immediately before and after the murders. Under "RECON," the locations of video cameras on nearby highways are listed.

Under a section called "NOTES," is the phrase, "The more you do the more clues you give," along with other tips allegedly gleaned from John Douglas' "Mindhunter" book on the profiling of serial killers.

From there, things get even more disturbing.

For "BODY PREP," the doc says, "Wash body inside and all cavities," "remove trace evidence [finger prints/hair]," "remove trace DNA," "remove ID marks [tattoos, marks]," "remove marks from torture," "remove head and hands," "package for transport." Many of these notes, investigators pointed out, directly correlated to the remains of Taylor and Mack.

The doc also included reminders to dispose of tools, clothes, "props, toys, wood items," and computer files.

Under the subhead, "THINGS TO REMEMBER," was written, "Sound travels," "Get sleep before hunt too tired creates problems," "hit harder ... consider a hit to the neck next time for take down," "More sleep & noise control = more play time" and "Use heavy rope for neck - light rope broke under stress of being tightened."

Per investigators, "Play time" is "believed to be a reference to sexual and mutilation acts perpetrated on victims."

The doc ends with reminders to "remember don't charge gas," to "recon" for more surveillance cameras and to not "hunt too long."

"We're going to continue to look at the cases," Tierney said on GMA. "We've got more bodies on Gilgo Beach and we have more bodies off of the beach as well, which has resulted in these two additional charges. We'll continue to work."

Heuermann has pleaded not guilty to the charges.

View full document below: