(NewsNation) —  Gilgo Beach killings suspect Rex Heuermann was in court Tuesday, wherein more discovery was handed over to his defense team.

Heuermann, 60, was charged last July in the deaths of three women; Melissa Barthelemy, Megan Waterman and Amber Costello, who were all found at Gilgo Beach in New York years ago. Earlier this year, Heuermann was charged with the death of a fourth: Maureen Brainard-Barnes. He has pleaded not guilty to all charges against him.

During court Tuesday, about 6,000 pages of information about Costello’s death were discussed.

At a news conference outside of court, Heuermann’s attorney, Mike Brown, alluded there was a different suspect in the case that the previous district attorney had identified and been ready to charge. That suspect had also been from Massapequa, Long Island, where Heuermann lived.

Now, the defense is looking for the leads and the tips that came in during the investigation of the women’s deaths, including who else might have been implicated.

No family members of Heuermann’s were sitting in the courtroom Tuesday, but Brainard-Barnes’ sister was.

The remains of multiple other people were found along Gilgo Beach between 2010 and 2011. On Tuesday, Suffolk County District Attorney Ray Tierney said the investigation into these cases is ongoing, but there is no new information to share at this time.

Heuermann’s court appearance for next year on will be April 17.