Billy Baldwin reveals he went to high school with Gilgo suspect Rex Heuermann

The Long Island man arrested in connection with the Gilgo Beach murders was a high school classmate of Billy Baldwin, the actor shared on social media Friday morning.

“Woke up this morning to learn that the Gilgo Beach serial killer suspect was my high school classmate Rex Heuermann,” Baldwin, 60, tweeted shortly before 11 a.m..

“Berner High School…Massapequa, New York…Class of 1981,” the “Flatliners” star continued.

Heuermann, 59, was still living in Massapequa Park when he was taken into custody in Manhattan on Thursday night.

He is due in court later Friday.

Baldwin — a younger brother of “30 Rock” star Alec Baldwin, 65 — was born and raised in Massapequa.

Follow The Post’s live blog for updates on the Gilgo Beach serial killings arrest

All four of the “Baldwin brothers,” who also include actors Daniel, 62, and Stephen, 57, graduated from Berner High, which is now a middle school.

The suburb is about a 20-minute drive from the Gilgo Beach area, where the bodies of four women were found in late 2010.

Other Berner High grads were quick to discuss Heuermann’s shocking arrest in a public alumni Facebook group on Friday.

“He used to leave me little love notes in my locker,” classmate Maureen Boyle Holpit wrote underneath a post announcing the development.

Who is Gilgo Beach serial killer suspect Rex Heuermann?

A suspected serial killer has been arrested over the notorious Gilgo Beach murders in Long Island, The Post can confirm.

Rex Heuermann, 59, a married architect at a New York City firm, has a home on 1st Avenue in Massapequa Park, sources told The Post.

His arrest is tied to the “Gilgo Four,” four women — Melissa Barthelemy, 24, Megan Waterman, 22, Amber Lynn Costello, 27, and Maureen Brainard-Barnes, 25 — found wrapped in burlap within days of each other in 2010. 

The body of Barthelemy was first found along Ocean Parkway on Dec. 11, 2010, sparking fears of a serial killer in the area.

By spring 2011, the number of bodies had climbed to 10, including eight women as well as an unidentified man and toddler.

Heuermann’s arrest comes after Suffolk County’s new police commissioner created a special Gilgo Beach Homicide Investigation Task Force in February 2022.

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“Omg I hope he goes to hell,” Massapequa resident Barbara Gaulrapp-Cox added.