GILGO BEACH MURDERS: OVER 200 GUNS TAKEN FROM SUSPECT'S HOME

Las Vegas police said they are "currently reviewing our unsolved cases to see if he has any involvement".

In addition to the 200 to 300 firearms found in a locked vault at the residence, officials also took a portrait of a woman with a battered face, according to New York Post reporters. 

Suffolk County Police Commissioner Rodney Harrison told Fox News in an interview on Monday: "He had an arsenal in a vault that he had downstairs."

"Anytime somebody has that type of arsenal we have some concerns," he added.

Mr Harrison told CNN that family members of the suspect - a married father-of-two - are reeling from the charges.

"They were disgusted," he said. "They were embarrassed."

The suspect is accused of killing three women whose bodies were found close together in 2010 on Gilgo Beach, on the South Shore of Long Island. 

Investigators have said they expect to charge him with the murder of a fourth woman: Maureen Brainard-Barnes.

The women, dubbed the Gilgo Four, were among 11 sets of human remains found on the beach, 50 miles (80km) east of New York City. 

A law enforcement source told CNN that as the suspect was being processed at jail following his arrest last Thursday, he asked staff: "Is it in the news?" 

Watched by journalists and members of the public, investigators have been searching his ramshackle home in Massapequa Park, a 20-minute drive from Gilgo Beach. 

Neighbours and Long Island residents were astonished by the arrest of the suspect, who owns a Manhattan architecture firm. 

After years of few leads in the cold case, investigators were able to charge him using mobile phone records, DNA evidence from a pizza, and a description of the killer and his vehicle.