Suffolk County police say a pizza box thrown into a Midtown garbage can help crack a long, unsolved murder case known as the “Gilgo Beach Murders.”

“Fresh eyes on this case and the resiliency of our investigators allowed us to identify Rex Heuermann,” said Suffolk County Police Commissioner Rodney Harrison.

DNA swabs from that pizza box led to the arrest of 59-year-old Rex Heuermann.

He’s charged with the murder of three women whose remains were found along a bay on Long Island in 2010.

Melissa Barthelemy, Megan Waterman and Amber Costello. Barthelemey lived in the Bronx.

“Rex Heuermann is a demon that walks among us. A predator that ruined families. If not for the members of this task force he’d still be on the streets today,” said Harrison.

Heuermann is a New York-based architect.

On Friday, Suffolk County police removed evidence from his firm’s headquarters on Fifth Avenue.

Police say new information and new technology led them to Hueremann last year and that they’ve been quietly on his tail ever since.

Evidence from the bail application shows Heuermann used burner phones and a burner email account to search topics such as “why hasn’t the Long Island serial killer been caught?”

Investigators say, a Chevrolet avalanche described by a witness to Amber Costello’s disappearance was the same as one registered to Heuermann.

Police also identified cell towers connected to the burner phones — one in Midtown and one in Massapequa Park, Long Island, where Heuermann lived with his wife and children.

This case, though, involves discovered remains of 11 victims — most of whom were sex workers.

Police say this investigation is far from over.

“Even with this arrest, we are not done. There’s more work to do in this investigation regarding other victims. Other Gilgo beach bodies that were discovered. I’m going to encourage anybody that still has information to call our Crime Stoppers hotline 1-800-220-TIPS,” said Harrison.

Heuermann is charged with first and second degree murder.

He pleaded not guilty in Riverdale Friday and is held without bail.

Heuermann is also a prime suspect of another killing in this case.