Rex Heuermann’s defense team made a big ask before a Suffolk County judge at a hearing Wednesday.

Defense attorney Michael Brown requested the judge split the case into five separate trials. If approved, it would group the first three victims of the original Gilgo Four - Megan Waterman, Melissa Barthelemy and Amber Costello - into one case. There would then be separate trials for the four remaining victims: Maureen Brainard-Barnes, Jessica Taylor, Sandra Costilla and Valerie Mack.

Brown said it would give Heuermann the best chance at a fair trial.

“There are so many difference from those three and those three also in some respects are different from each other,” Brown said. “So, the answer is they should be tried separately so that there's not prejudice to the defendant."

Suffolk County District Attorney Ray Tierney said he will submit a response in opposition that would keep the case as one.

Tierney also met a critical deadline Wednesday by filing a response to the defense’s motion to dismiss some of the DNA evidence in the case.

Brown has argued there were errors from the lab where the DNA was analyzed.

Tierney rejected that and defended the technology.

“This is the next generation of the evolution of the technology,” Tierney said. “It's exciting to be at the forefront of that. We look forward to proving the scientific acceptance."

The testing methods used by a California-based company have never been presented in a New York courtroom before. DNA is a massive part of the district attorney’s case against Heuermann. Prosecutors say the genetic testing done on hairs found on the victims connects them to Heuermann.

Heuermann, who was arrested in July 2023, has pleaded not guilty to killing seven women between 1993 and 2011.

He is due back in court on Feb. 18.