This question became central to the mystery.
A shark entering a tidal creek is biologically possible.
Matawan Creek is connected to coastal waters, meaning an animal moving through the estuarine system could enter it.
New Jersey itself supports a remarkably diverse marine ecosystem. The state’s Fish and Wildlife agency notes that hundreds of marine finfish species can occur in New Jersey bays, estuaries and marine waters, including multiple shark species.
But one question has remained controversial for more than a century:
What species attacked the Matawan victims?
For decades, the most famous answer was a great white shark.
That conclusion became connected to another dramatic event that happened shortly after the attacks.
A large shark was caught nearby.
And according to contemporary reports, investigators found something inside it that seemed to solve the entire mystery.
Human remains.
Except the case was never quite that simple.
The Shark That Was Caught
Not long after the New Jersey attacks, a large shark was captured by a man named Michael Schleisser.
The animal was identified in contemporary accounts as a young great white.
Newspapers reported that human remains were found inside its stomach.
The implication was obvious.
The killer had been caught.
The shark was displayed publicly, and the story appeared to provide a satisfying conclusion to an event that had terrified the coast.
But modern investigators have reasons to be cautious.
Burgess explained that the International Shark Attack File could not independently verify important parts of the historical account.
There were limitations in the surviving documentation.
Modern researchers did not have the quality of photographs that would allow easy confirmation of the species. Nor was there a surviving modern-style forensic record conclusively proving that the reported human remains belonged to the Matawan victims.
The historical press identified the captured animal as a white shark.
But more than a century later, absolute certainty is difficult.
And Matawan Creek itself creates another possibility.
Was It Actually a Bull Shark?
This is where the mystery becomes even more interesting.
Great white sharks can enter relatively shallow coastal environments.
But another species is famous for doing something particularly relevant to Matawan:
bull sharks can tolerate fresh and brackish water.
They have been documented entering rivers and traveling considerable distances inland.
That ability makes a bull shark seem like an intuitive candidate for attacks occurring inside a creek.
Some later researchers and writers have therefore suggested that a bull shark may have been responsible for the Matawan incidents.
Others continue to argue that a great white remains plausible, especially given the shark captured after the attacks and the possibility that one animal was responsible for the larger 1916 sequence.
There is no surviving DNA sample from the attacker.
There is no modern forensic examination.
There is no underwater footage.
The evidence comes from eyewitness testimony, newspaper reporting, injury descriptions and the shark captured afterward.
That leaves room for debate.
And it creates another question.
Was there actually one shark?
One Predator—or Several?
Popular retellings often present the 1916 attacks as the work of a single rogue shark moving north along the New Jersey coast.
It makes for an extraordinary narrative.
Beach Haven.
Then Spring Lake.
Then Matawan Creek.
One predator traveling along the coast and finally moving inland.
But nature does not have to follow the clean structure of a thriller.
Multiple sharks could have been responsible.