Suffolk County District Attorney Raymond Tierney is expected to announce a new "significant" development in the Gilgo Beach Homicide Task Force investigation following the suspected killer, Rex Heuermann's court appearance later this morning.

The Massapequa Park man, who was arrested in July 2023, is accused of killing six women dating back to 1993. He is also the prime suspect in the death of a seventh victim, Valerie Mack.

Heuermann's appearance is scheduled for 9:30 a.m. in front of Supreme Court Justice Hon. Timothy Mazzei in Riverhead.

Suffolk County Sheriff Errol Toulon, Jr., Acting Suffolk County Police Commissioner Robert Waring, members of the New York State Police and representatives from the Gilgo Beach Homicide Investigation Task Force are scheduled to join Tierney at a press conference following Heuermann's court appearance.

Defense attorney Michael Brown is also expected to speak with the media later today.

Heuermann last appeared in court on Oct. 16 where Brown argued to exclude certain DNA evidence from the trial. Judge Mazzei told prosecutors he wanted to see all discovery turned over to Brown by today.