Meanwhile, boat operator Jojo K. John, 35, has been arrested.
"We have probable cause to believe that he operated the boat while intoxicated," Van Cura said.
John was arraigned at an area hospital on one count of first-degree vehicular manslaughter and three counts of second-degree vehicular assault. More charges are possible, Van Cura said.
John, along with the others who were not thrown from the boat, suffered head injuries.
Bond, the groom, was hospitalized at Westchester Medical Center, said Stewart's stepfather Walter Kosik, who visited him Saturday. "He was in no condition to talk."
A spokesman for the medical center said Bond was in fair condition, with serious head injuries. He was the one who called 911 from the boat, reporting the accident.
For the families, the tragedy was magnified by the pending nuptials.
"She's supposed to be married two weeks from today," said Carol Stewart about her daughter. "It just can't end like this."