The Long Island man was charged in the death of Valerie Mack, whose remains were found in 2000 and 2011, according to an indictment unsealed Tuesday. Heuermann pleaded not guilty in all seven murders.

Rex Heuermann was charged in the death of Valerie Mack, whose remains were found in 2000 and 2011, according to an indictment unsealed Tuesday. Heuermann pleaded not guilty to all seven murders.

Accused Gilgo Beach serial killer Rex Heuermann is being charged with a seventh murder: the death of Valerie Mack, officials said.

Prosecutors have linked Rex Heuermann to the death of several other unsolved killings, including Valerie Mack, a New Jersey woman whose remains were discovered in Manorville and near Gilgo Beach.

The District Attorney’s office lacks the resources to meet "ambitious" deadlines imposed by the judge overseeing the Gilgo Beach case, the DA said.

The District Attorney’s office lacks the resources to meet "ambitious" deadlines imposed by the judge overseeing the Gilgo Beach case, the DA said.

It is not clear if the death of "Asian Doe" can be linked to Rex Heuermann, who has been charged in six of the Gilgo Beach murders.

A new sketch of the Gilgo Beach victim known as "Asian Doe," whose remains were recovered along Ocean Parkway in April 2011, was released Monday.

A new sketch of the Gilgo Beach victim known as "Asian Doe," whose remains were recovered along Ocean Parkway in April 2011, was released Monday.

Rex Heuermann appeared in court – authorities have received more than 7,000 tips since his arrest last year. He has pleaded not guilty.

Since Rex Heuermann's arrest, prosecutors revealed in court on Tuesday that they have received over 7,000 tips and are considering additional charges.

Prosecutors reveal details gleaned from 350 devices seized from Rex Heuermann’s home including an alleged blueprint and plan for his kills.

Prosecutors charged Rex Heuermann with two additional murders Thursday morning, revealing a trove of evidence that expands the murder investigation timeline to over three decades.

Suffolk County District Attorney Raymond Tierney joins “GMA” to discuss the new developments in the case of Rex Heuermann after he was charged with two additional murders.

Suffolk County District Attorney Raymond Tierney joined ABC News' “Good Morning America” on Friday.

Heuermann was charged Thursday with the murders of two additional women, bringing his total number of alleged killings to six.

Gilgo Beach suspect Rex Heuermann has been charged with two additional murders and is now accused of killing six women dating as far back as 1993.

The alleged Long Island serial killer appeared in court Thursday morning to face new charges in connection with the murders of two more women.

The search for missing sex worker Shannan Gilbert led to the grisly discovery of 10 other bodies on a stretch of beach along Long Island's South Shore.

Rex Heuermann is now charged with the 2003 murder of Jessica Taylor and the 1993 murder of Sandra Costilla, bringing the total to six.

Investigators searched Rex Heuermann's home as recently as May. Authorities also searched a wooded area on Long Island in April as part of the investigation, according to law enforcement sources.

The new indictment would follow searches at Heuermann's home and a wooded area where remains of two women were previously found.

Newsday reports Heuermann will face charges in connection with a fifth victim.

Newsday reports the new charge follows a recent search of his home in Massapequa Park and the search of a wooded area where two victims were found more than a decade ago.

A new search at the home of accused Gilgo Beach serial killer Rex Heuermann in Massapequa Park indicates the issuance of a new search warrant for potential new evidence in the case.

ABC News’ Erielle Reshef reports on the deepening mystery as investigators scour a wooded area roughly 45 minutes east of the infamous Gilgo Beach, where bodies were discovered.

Investigators are searching a wooded area in Manorville, New York, as part of the Gilgo Beach murders investigation, law enforcement sources told ABC News.

Investigators are searching a wooded area in Manorville, New York, as part of the Gilgo Beach murders investigation, law enforcement sources told ABC News.

In the statement, Asa Ellerup said she is giving her husband, Rex Heuermann, "the benefit of the doubt" and that she will "withhold judgment until the end of the trial."

The estranged wife of alleged Gilgo Beach serial killer Rex Heuermann maintains that he is "not capable of the crimes he is accused of," her attorney said Wednesday.

ABC News correspondent Stephanie Ramos and ABC News contributor Brian Buckmire share the latest as the Gilgo Beach suspect entered a not guilty plea to a fourth murder charge.

Prosecutors in Suffolk County, New York, have charged alleged serial killer Rex Heuermann with murdering Maureen Brainard-Barnes.

Host and legal analyst at the Law and Crime network, Terri Austin, provides analysis on the latest details in the Gilgo Beach and Murdaugh murder cases.

Rex Heuermann, 60, was charged with murdering Maureen Brainard-Barnes, who disappeared in 2007 while working as an escort.

Investigators released new evidence against Rex Heuermann, who was charged with the murder of Maureen Brainard-Barnes, months after he was IDed as the primary suspect. He has pleaded not guilty.

Rex Heuermann was charged with murdering Maureen Brainard-Barnes, who disappeared in 2007.

ABC News’ Stephanie Ramos and contributor Channa Lloyd talk about what the new charges that suspect Rex Heuermann faces and what new evidence could mean for the case.

Alleged serial killer Rex Heuermann has pleaded not guilty to a new second-degree murder charge.

Heuermann has already pleaded not guilty to three other murders.

Alleged serial killer Rex Heuermann will appear in court Tuesday to be charged with killing a fourth woman whose body was found in a marshy spot on Long Island near Gilgo Beach, sources tell ABC News.

Alleged serial killer Rex Heuermann is expected to be charged in the death of a fourth woman in New York. ABC News' Lionel Moise has the details.

Rex Heuermann is already charged with killing three women. He will return to court on Tuesday.

Lawmakers are pushing for an expansion of a state law that prohibits convicts from profiting from their crime.

A DNA sample taken from the estranged wife of alleged serial killer Rex Heuermann matches her genetic material that was found on the remains of victims, law enforcement sources told ABC News.

Prosecutors have cleared Asa Ellerup of any wrongdoing and have said she was out of town at the time of the murders.

Asa Ellerup attended one of Rex Heuermann's court appearances for the first time on Wednesday surrounded by a film crew after signing a contract with a production company.

The estranged wife of Gilgo Beach, New York, murder suspect Rex Heuermann attended one of his court appearances for the first time on Wednesday.

Asa Ellerup, the estranged wife of suspect Rex Heuermann, attended his hearing Wednesday saying she wants to see the evidence against him.

ABC News’ Aaron Katersky has the details as the Gilgo Beach murder suspect appears in court.

Gilgo Beach suspect Rex Heuermann is not a "monster" and maintains his innocence, his attorney said.