The admission came 10 days after her fiancé, Vincent Viafore, 46, disappeared in the Hudson river.  Graswald was visiting Bannerman Island, where the couple had stopped on the day of the drowning, and ran into investigators who were searching for clues to the episode, which was still being treated as an accident.
Graswald, revealed that she had removed the plug from the kayak and sabotaged the paddle, according to police testimony. She allegedly confessed that after Mr. Viafore capsized, and was holding onto his kayak and a dry bag for flotation, he had begged her to call 911, but that she “kind of reached over and took his paddle from him and strapped it onto her kayak.”
The testimony by detective DeQuarto came on the fourth day of the hearing states that the Poughkeepsie, N.Y. residents set out in two kayaks from the western shore of the Hudson. They paddled to Bannerman Island, where, the police say, they spent a few hours drinking beer and taking pictures.

Viafore’s kayak dragged out of the Hudson by rescuers

On the return crossing, however, the boat belonging to Mr. Viafore, who was not wearing a life vest, capsized. He vanished under the choppy water, which at 46 degrees was cold enough to bring on hypothermia. For 10 days, Ms. Graswald was treated as a fiancée in mourning, while rescuers searched for the body.
On April 29, investigator officers ran into Ms. Graswald on the island, a historic site with the ruins of a castle who was leaving flowers on the island for Mr. Viafore. She told them he had recently postponed their wedding.
DeQuarto said he  had asked her how she felt about Mr. Viafore’s death and she responded: “Fine. Over it.”
“She felt like herself,” she said. “She felt free.”
She went on to tell DeQuarto she was angry that Viafore, 46, had pressured her to have sex with him and another woman. She made statements about her fiancé  making “sexual demands to her, how he wanted to have threesomes with other women, how he made her have sex when he wanted sex.”
Graswald, according to the detective said Viafore even had a third partner in mind, a woman he knew, named Tina. He would say: “‘Why can’t you do a threesome with Tina?’ Tina would do this, Tina would do that. It made her upset.”
Asked why she did not break up with him, she responded “I’m a very spiritual person, I knew he would never be gone” if I only broke up with him.
DeQuarto said  when he asked, ‘Did you remove that plug so he would drown?’” Graswald paused for a moment then said, ‘I guess I did.’” She also admitted tampering with his paddle, the detective noted that the physically agitated Graswald had begun her confession on the island by saying that she “wanted to be free.”
“I wanted to go on and I wanted to be myself,” he recalled her saying, adding that she had later said of Mr. Viafore: “He trapped me.”
Graswald however, had also indicated that she could have pictured herself with Mr. Viafore if things had been different. “She wanted a normal life with Vincent, she wanted to get married, she wanted to have children.”

The kayaks used by the couple. Viafore was in the blue kayak.

She also accepted an invitation to come to the police station and continue in a more formal setting.On the way,  she expressed feelings of freedom and of wanting to buy a motorcycle to ride.
She was charged with murder the next day, after an 11-hour police interrogation.
Prosecutors have said that Graswald stood to collect $250,000 in life insurance benefits from his death.  Graswald was also aware that she was the primary beneficiary on two of Viafore’s life insurance policies, and “talked about what she could do with the money” after his death. She had told her interrogators about wanting to ‘buy and ride’ a motorcycle with the money.
Graswald’s attorneys who maintain that Viafore’s death was a tragic drowning, triggered by the waters of the rough, cold river after he drank too much and was overcome by the choppy waters. They are also attempting to suppress the 11-hour interrogation tape.
Earlier on, the defense had also argued that Graswald, who is originally from Latvia and is in the U.S. with a permanent resident card, is “very confident sounding, so even if she doesn’t understand what you’re saying, she’ll answer in an affirmative tone,” her lawyer said. “She was suffering from hypothermia and the loss of her fiance, and there was a very clear language barrier.”