Why cops arrested suspected Gilgo killer Rex Heuermann away from his home

Police arrested Gilgo Beach murder suspect Rex Heuermann near his Manhattan office due to worries about the arsenal of weapons at his Long Island home, officials said.

Heuermann, 59, had up to 300 guns in a vault in the basement of the rundown Massapequa Park home he shared with his second wife and two adult children.

“We wanted to take him into custody somewhere outside the house, because of access to those weapons,” Suffolk County District Attorney Ray Tierney explained to ABC News.

Of the hundreds of firearms, Heuermann is believed to have only had permits for about 92, officials previously said.

Former NYPD Chief of Detectives Robert Boyce told George Stephanopoulos reiterated TIerney’s concerns on “Good Morning America” on Tuesday.

“You don’t want to go into that house — you want to take him off premise,” he said.

“This way it’s safer for everybody.”

Heuerman was ultimately arrested by plainclothes police at his Fifth Avenue office late Thursday.

He pleaded not guilty on Friday to three counts each of first and second-degree murder in connection with the deaths of Melissa Barthelemy, Megan Waterman and Amber Costello.

He is also the primary suspect in the death of Maureen Brainard-Barnes.

Authorities spent the weekend combing through Heuermann’s home and the storage unit where he kept in Amityville.

Officials said on Monday that they were specifically looking for body parts or other “trophies” that could link the South Shore native to the Gilgo killings.

Investigators were spotted that same day removing a series of troubling items from the ramshackle red home, including a portrait of a battered woman with a black eye.

Police initially linked Heuermann to the so-called “Gilgo Four” – whose bodies were found in the marshes off Ocean Parkway near Gilgo State Park in December 2010 – through his first-generation Chevrolet Avalanche, which matched the vehicle linked to the unidentified killer, court documents revealed.

Mobile phone bills later tied Heuermann to the burner phones used to contact the victims and taunt at least one of their families.

A slew of additional evidence against Heuermann – including gruesome porn searches and a fake Tinder account – eventually led police to test his DNA found on a discarded pizza crust.

The sample was matched to a male hair found on the burlap used to wrap Waterman’s body, the bail application stated.

A total of 11 bodies, mostly women, were found in the Gilgo Beach area starting in 2010.

It is unclear if he is tied to any of the other Gilgo bodies, including that of Shannan Gilbert, whose May 2010 disappearance sparked the search that uncovered the other victims. 

As of Tuesday morning, Heuermann is being held on suicide watch while police continue their investigation into the former cold case.