COPS have raided a storage unit allegedly belonging to Long Island Serial Killer suspect Rex Heuermann, whose attorney released a statement following his arrest.

Heuermann, 59, was arrested on Thursday before law enforcement surrounded his home in Massapequa Park, New York – about 30 miles east of New York City.

Heuermann was charged with three counts of first-degree murder and three counts of second-degree murder by a grand jury on Friday afternoon.

Those charges are for the deaths of three victims – Melissa Barthelemy, 24; Megan Waterman, 22; and Amber Costello, 27, three of the four women known as the Gilgo Four.

The alleged murderer pleaded not guilty and is due back in court on August 1.

But the investigation continues, as police have been spotted searching a storage unit in relation to the case.

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"We have executed a search warrant for one of the storage units in relation to the Gilgo suspect case," Det. Lieutenant Kevin Beyrer told News 12 Long Island.

The search occurred on Sunday at a facility in Amityville about two miles east of Massapequa Park where Heuermann was arrested last week.

News 12 reported that as of Monday morning, a police presence was still at the storage unit.

It is not yet clear to whom the storage unit belongs.

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News of the storage unit search comes as Heuermann's attorney released a statement to News 12 indicating other leads in the case for police to follow.

“Rex Heuermann is 59 years old with no prior criminal history. He is a college graduate and is a hardworking licensed architect who has his own NYC firm," the attorney told the outlet.

"He is a loving husband to his wife of over 25 years and an involved and dedicated father to his daughter and stepson.

"He has entered a not guilty plea and has insisted he did not commit these crimes.

"There is nothing about Mr. Heuermann that would suggest that he is involved in these incidents.

"And while the government has decided to focus on him despite more significant and stronger leads, we are looking forward to defending him in a court of law before a fair and impartial jury of his peers.”

ARREST MADE

Heuermann was described in an online profile as having over 30 years of experience and has worked with large corporate clients, including American Airlines.

Officers surrounded Heuermann's home late Thursday night and remained close to the residence "all night," an eyewitness told The U.S. Sun.

They also noted that a "large cooler" was removed from the architect's house.

Investigators said they were able to arrest Heuermann after they recovered his DNA from a discarded pizza box, according to a police report.

A single strand of Heuermann's hair was allegedly found on one victim.

An attorney for families of two murdered women linked to the case told The U.S. Sun he had been receiving taunting and threatening phone calls from a man and woman for months - but they ended a week before suspect Rex Heuermann's arrest.

John Ray, who represents the families of Shannan Gilbert and Jessica Taylor, said he expects more arrests to be made.

MAJOR BREAKTHROUGH

The arrest is a major breakthrough in the ongoing case that has gone unsolved over a decade, per Gilgo News.

Last year, Nassau and Suffolk County police stepped up their investigation into the case, with the FBI and New York State Police joining forces to solve the murders.

Law enforcement personnel have been hunting for a suspect since 2010 after the body of Melissa Barthelemy, 24, was found near Gilgo Beach, about a half-hour drive from the home.

A Suffolk County Police Officer and sniffer dog discovered her skeletal remains in the brush just off Ocean Parkway on December 11 of that year.

Barthelemy was a sex worker who had disappeared from the Bronx in 2009.

Over the course of the following days, police located the remains of three other women.

Megan Waterman, 22, Amber Lynn Costello, 27, and Maureen Brainard-Barnes, 25, were all discovered within the same area of Gilgo Beach.

They were all wrapped in burlap.

GILGO FOUR

As 2011 began, police suspected the "Long Island Serial Killerbody count to be at least 10 after they discovered the remains of four additional women, an unidentified man, and a toddler.

Another pair of remains belonged to New Jersey sex worker Shannan Gilbert, 24, who disappeared after leaving a client's house near Gilgo Beach in 2010.

Gilbert managed to call 911 before her death, noting that she feared for her life.

The call was never released publicly, but The U.S. Sun obtained the recorded conversation with police dispatch, where Gilbert could be heard banging on doors and saying, "they're gonna kill me."

At 4.51am on May 1, as she left the house on foot, Gilbert repeatedly told dispatchers: "There's somebody after me."

She then asked: "Can you trace where I am?"

Police were unable to locate her, and she was never seen alive again.

Gilbert's late mother and the family attorney, John Ray, maintained that she was being targeted by the serial killer when she died.

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However, Dominick Varrone, the former chief of detectives at the time of the disappearances of the Gilgo Four, said that the circumstances surrounding her death don't match those of the other victims.

The Gilgo Four includes Megan Waterman, 22, Amber Lynn Costello, 27, Maureen Brainard-Barnes, 25, and Melissa Barthelemy, 24, all of whom were found whole, wrapped in burlap, and discovered about one-tenth of a mile apart from each other on Gilgo Beach.