Investigator Testifies that Angelika Graswald Confessed to Sabotaging Fiancé's Kayak Because of Souring Relationship: 'I Wanted to Be Free'

A New York State police investigator told a courtroom on Monday that Angelika Graswald confessed to him that she caused her fiancé's death by sabotaging his kayak because she was upset over their souring relationship.

"I wanted to be free, I wanted him gone, I wanted to be myself," Donald DeQuarto testified Graswald allegedly told him during a private one-hour conversation. The conversation took place at Bannerman Island in New York's Hudson River on April 29, 2015 – ten days after the kayak of Graswald's fiancé, Vincent Viafore, capsized nearby and he disappeared into the rough waters.

DeQuarto testified that Graswald allegedly admitted she removed a plug from Viafore's kayak, which caused his death.

"He trapped me," DeQuarto testified Graswald told him.

The testimony took place during the fourth day of a pretrial hearing in an Orange County, New York courtroom. The purpose of the hearing is to review the manner in which the police obtained statements from Graswald. Her attorney, Richard Portale, seeks to suppress an 11-hour interrogation video, which features the alleged confession.

Graswald is charged with second-degree murder in the death of Viafore, whose body was recovered in mid-May of last year.

When he asked Graswald if she thought Viafore would drown if she removed the plug, Graswald said yes, the investigator testified.

According to DeQuarto, Graswald allegedly revealed how she caused Viafore's death: She allegedly removed a plug from the kayak and stashed the plug in their home. She allegedly removed a piece of the kayak's paddle. And, once Viafore was in the water and struggling without a life vest, she allegedly snatched his paddle from him.

Graswald told DeQuarto about troubles in her relationship with Viafore, DeQuarto testified.

"She explained how Vince would make these sexual demands, how he wanted threesomes and demanded sex when he wanted sex and that made her feel trapped and made her want to be free," DeQuarto testified.

"I asked her why she didn't break up with him," he said, "and she said she was a spiritual person" and that he would not be truly gone if she did.

Under questioning by Portale, DeQuarto admitted he didn't take notes and did not record the conversation he had with Graswald during their private walk on the island. The first time he wrote down his recollection of their conversation and her alleged confession was about 15 hours after their talk at 3 a.m. the next morning, DeQuarto testified.

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Around 4 p.m. on April 19, Graswald, 36, and Viafore, 46, had set out from the mainland to Bannerman Island in fairly calm waters. DeQuarto said they spent several hours on the island taking photos, and didn't leave when they saw the seas becoming choppy and rough because they were having fun.

At about 7 p.m., on their return trip to the mainland, Viafore used his flotation device as a back rest, DeQuarto told the court.

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.

Portale has said Viafore died accidentally when his kayak capsized and he fell into the cold and rough waters.

Testimony continues Monday afternoon.