Investigators who searched the Long Island, New York, home of the suspect in the Gilgo Beach serial killings, Rex Heuermann, discovered a Microsoft Word planning document that they say provided a blueprint for the killings of several women, authorities in Suffolk County announced Thursday.

Heuermann, who had already been charged in the deaths of four women, known as the Gilgo Four Melissa Barthelemy, 24, Maureen Brainard-Barnes, 25, Amber Lynn Costello, 27, and Megan Waterman, 22 was arraigned Thursday on additional charges of murder in the deaths of Jessica Taylor, 20, and Sandra Costilla, 28.

Heuermann, a 60-year-old architect, has pleaded not guilty.

His defense attorney, Micheal Brown, told CNN that his client is in a bad place in terms of the new charges.

One murder is obviously horrific, and its a difficult thing to defend, Brown said after Heuermann appeared in court Thursday. And now were at six.

Brown did not respond to a request for comment from HuffPost.

The new charges follow a lengthy investigation and search of Heuermanns Massapequa Park home, where detectives collected possible evidence that included more than 350 electronic devices. They said they found images depicting violent sexual acts on the devices, along with the chilling document that they alleged planned out the slayings, according to a bail application released Thursday.