Gilgo Murders

We now know more about what happened when cops arrested the suspected Gilgo Beach serial killer -- we're told the guy didn't put up much of a fight.

Suffolk County Police Commissioner Rodney Harrison tells TMZ Rex Heuermann was taken into custody without issue .. and despite being suspected of committing heinous crimes, we're told Heuermann remained stoic throughout the process of his arrest.

Here's how it went down, per Harrison -- he says Heuermann was approached by detectives on the streets of NYC Friday ... who then told him he was under arrest. We're told Heuermann asked what for, and they told him it was for his alleged involvement in the Gilgo Beach murders from over a decade ago.

Harrison says Heuermann's response was interesting ... all he apparently said to the arresting officers was "I didn't do that" -- but we're told he did so in a very somber way. We're told he didn't shout or vehemently deny anything ... he just calmly said it wasn't him.

Harrison says they then threw on the bracelets, and that Heuermann didn't resist whatsoever -- he went peacefully and quietly with them. Commissioner Harrison tells us the detectives subsequently read him his Miranda Rights, and that he requested a lawyer.

Some believed his detainment was a bit more dramatic -- especially with footage that's been released showing police trailing him out and about -- however, it was anything but.

As we reported ... NY officials allege Heuermann is responsible for the 2010 deaths of Megan Waterman, Melissa Barthelmey and Amber Costello. Cops also suspect he may have murdered Marueen Brainard-Barnes -- the 4th victim -- but he hasn't been charged for that murder yet.

The suspected Gilgo Beach serial killer may have had a female accomplice for the 3 victims ... at least according to a lawyer representing the families.

Attorney John Ray, who reps the families of slain Shannan Gilbert and Jessica Taylor, claims Rex Heuermann was not a solo operator and allegedly killed 3 prostitutes on Long Island with help from a mysterious cohort. Police have not linked the Gilbert and Taylor slayings to Heuermann as of now.

Ray pointed to the 2011 death of a 10-month-old baby girl whose body was found swaddled in a blanket near one of the confirmed Gilgo Beach victims. The lawyer insisted that a savage murderer would not have such maternal instincts to wrap the infant in a quilt.

"It's that kind of thing that, if you're such a depraved murderer, you don't take time to do. That to me seems like an act of a mother," Ray said, adding, "We also believe that some of the victims could've been lured by a woman."

Suffolk County Police officials have not commented on Ray's accusations on whether Heuermann had a cohort or if he's being eyed for the baby's murder.

But, Heuermann has enough legal problems to keep him busy. Detectives arrested him last week as he walked from his office in NYC, where he worked as an architect.

Prosecutors charged Heuermann with the murders of three sex workers and he's the top suspect in a fourth slaying. Heuermann allegedly wrapped their bodies in burlap and dumped them near Gilgo Beach between 2009 and 2015.

According to court documents, Heuermann was connected to the crimes through DNA testing and examining his cell phone records.

There's been a breakthrough in the Gilgo Beach murders case ... a suspected serial killer is now in police custody on Long Island.

Rex Heuermann, an architect from Long Island who works at a firm in New York City, was taken into custody Friday in connection with some of the killings from over a decade ago ... according to multiple reports.

You may recall, the Gilgo Beach murders case started capturing national attention way back in 2010 ... when police discovered four bodies wrapped in burlap during a search for Shannan Gilbert, a sex worker who vanished on Long Island.

The bodies, known as the "Gilgo Four," were ultimately identified as Amber Lynn Costello, Maureen Brainard-Barnes, Megan Waterman and Melissa Barthelemy. The woman were all reportedly sex workers in their 20s.

Police have long believed a serial killer was responsible for the women's deaths ... but the investigation never really turned up much over the years, until Friday's arrest.

In total, 11 sets of human remains have been found on Gilgo Beach ... including Gilbert's and those of Valerie Mack, a sex worker who had been missing for over 2 decades ... plus a man and a toddler.

Heuermann was arrested after being matched with DNA, according to the New York Post, and he's expected to be arraigned later today.

Police have cordoned off Heuermann's home in Massapequa ... and the place is crawling with law enforcement.

The district attorney is set to address the arrest around 4 PM ET Friday during a news conference.