Suffolk County District Attorney Ray Tierney sat down with News 12's Rich Barrabi for an interview regarding the Gilgo Beach investigation.

MORE: ‘A devastating time’: Attorneys for Rex Heuermann’s wife say arrest has taken ‘emotional toll’ on family, request privacy

Tierney says he ran for district attorney with the promise to start a task force into the Gilgo Beach murders.

LIVE BLOG: Updates on the case as they happen 

He says the first meeting of the task force was on Feb. 1, 2022. Six months later, Rex Heuermann had been identified as a suspect in the Gilgo Beach murders for the first time.

"As we looked at it, given what has been traditionally called the Gilgo Four, given the similarities in their murders, we figured that was the best place to start," Tierney said.

WATCH: DOCUMENTARY AND BACKGROUND INFORMATION - Gilgo Beach: Unsolved

Since March 14, 2022, he says there has been a lot of intensive work. Tierney says they will continue to work on the fourth murder case in which Heuermann is a prime suspect.

Tierney also says they are going to investigate the other Gilgo Beach murder cases.

"Right now, we can prove these cases," Tierney said. "We're going to work all of the investigations involving Gilgo, and we're going to let the evidence dictate our next actions."

More of News 12's interview with the district attorney can be seen on Tuesday at 7 p.m.