By Diane Herbst
Updated June 09, 2016 12:00 PM
Credit: Allyse Pulliam/Times Herald-Record/AP

The hearing is to determine if statements Graswald made to investigators can be admitted at trial.

Vincent Viafore, 46, drowned on April 19, 2015 in the Hudson River after his kayak capsized in rough seas and windy conditions. He and Graswald were kayaking back to the mainland from an afternoon on on island in the Hudson called Bannerman’s Island.

Graswald, 36, has pleaded not guilty to charges of second-degree murder and second-degree manslaughter in the death of Viafore, whose body was recovered on May 23, 2015.

Prosecutors have said that Graswald pulled a plug from the top of Viafore’s kayak, and once he capsized and struggled in the frigid waters of the Hudson River Graswald moved his paddle from him as he was struggling to stay afloat, and that she didn’t call 911 fast enough.

The motive, prosecutors say, is that Graswald was the primary beneficiary on Viafore’s two life insurance policies, and stood to gain $250,000 if he died.

Graswald’s attorney, Richard Portale, has said that Viafore, who was not wearing a life vest, died accidentally when his kayak capsized and he fell into the frigid water.

Kayaking and hypothermia experts have told PEOPLE that it was a dangerous day to be out on 46-degree waters without a life jacket or wet suit, and that the kayaks Viafore and Graswald used were not suited to handle the turbulent Hudson.

In the days after Viafore’s disappearance, Graswald worked closely with investigators. She even invited them to a nightclub gathering to honor Viafore. “…she was being treated like a grieving widow,” state police investigator Aniello Moscato testified Tuesday.

That all changed when Graswald allegedly told investigators that she had pulled a small drain plug from the top of Viafore’s kayak.