An American couple who was feared dead after their catamaran yacht was hijacked by three escaped prisoners were likely thrown overboard in the Caribbean Sea, authorities said Monday.

Ralph Hendry, 66, and his wife, Kathy Brandel, 71, were last known to be near Grand Anse Beach in Grenada. Their catamaran, named "Simplicity," was found abandoned in St. Vincent and there were signs of violence at the scene, according to Royal Saint Vincent and the Grenadines Police Force spokesperson Junior Simmons.

Although family, friends, and members of the sailing community had hoped the pair was still alive, police in St. Vincent and the Grenadines said Hendry and Brandel were likely thrown into the ocean when their vessel was hijacked. "Based on the investigation thus far, it is presumed that Ralph Hendry and Kathy Brandel are deceased," Simmons said in a video statement Monday.

Don McKenzie, police commissioner of the Royal Grenada Police Force, said at a news conference Monday that the three prisoners escaped on Feb. 18 from the South St. George Police Station. They hijacked the catamaran on the following day and traveled to the nearby island of St. Vincent, where they were arrested last Wednesday, he said.

Police: Prisoners 'disposed' occupants of Simplicity

After escaping from the South St. George Police Station, McKenzie said the three prisoners "commandeered" the catamaran, which had two U.S. citizens on board, Hendry and Brandel. The couple were likely thrown into the ocean and died, police in Grenada said.

“Information suggests that while traveling between Grenada and St Vincent, they disposed of the occupants,” McKenzie said.

McKenzie added that while police have "nothing conclusive" to prove that the couple was dead, he cited a "low probability" they were alive.

The suspects are being investigated for several criminal acts, including "bodily harm to the couple," according to Simmons. Authorities discovered signs of violence on the couple’s boat after it was found abandoned, he said.

"Several items were strewn on the deck and in the cabin, and a red substance that resembles blood was seen on board," Simmons said.

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Police investigating prisoners' escape

According to the Royal Grenada Police Force, the escaped prisoners were identified as Ron Mitchell, 30; Trevon Robertson, 19; and Abita Stanislaus, 25.

All three were arrested and charged in December with one count of robbery with violence. Mitchell also was charged with one count of rape, three counts of attempted rape, and two counts of indecent assault and causing harm, police said.

McKenzie said police have launched an investigation into the escape and are looking into whether it was "a system failure" or a case of a "slip up."

"All aspects of that investigation are on the table," he said, adding that the police holding station where the three men were being held has "sufficient safety to prevent an incident like that (from) occurring."

The three men appeared in court in St. Vincent on Monday and pleaded guilty to four counts each of immigration-related charges, including entering the island as a "prohibited immigrant" with no passport, according to Simmons. They are scheduled to be sentenced on those charges in March.

Simplicity discovered by paddle-boarder near St. Vincent

The Salty Dawg Sailing Association said it was alerted by a cruising skipper about Simplicity, which was found "anchored and abandoned" off a beach on the island of St. Vincent. The association added that its live member’s tracking map showed the vessel anchored in Grenada before it moved to its last anchorage off St. Vincent.

"The good Samaritan had boarded the boat and noted that the owners … were not on board and found evidence of apparent violence," the association said in a statement. 

People reported that a sailing captain was paddle-boarding near St. Vincent when he noticed the catamaran with a broken sail. When he boarded Simplicity, he found the deck covered in blood and two passports belonging to Brandel and Hendry, according to People.

The St. Vincent Coast Guard took possession of Simplicity and local police are investigating with the U.S. Embassy and the Grenada police, according to the association.

Family, sailing community mourns couple's disappearance

According to a GoFundMe page raising money for the couple's families, Hendry and Brandel were "seasoned sailors who lived on their beloved catamaran." The pair spent their retirement sailing, the GoFundMe page states.

"This heartbreaking tragedy has left not only the sailing community, but also their families, shattered," the GoFundMe page states, adding that Brandel had recently welcomed her first grandchild.

The couple had sailed their yacht in last year's Caribbean Rally from Hampton, Virginia, to Antigua, and were spending the winter cruising in the eastern Caribbean, the Salty Dawg Sailing Association said. The association noted that the couple were veteran cruisers and longtime members of the association from its earliest days.

"Warm-hearted and capable, they both contributed to building the SDSA and Kathy sat on the association’s board for two years," the association said.

In a statement from the couple's families on Saturday, they thanked authorities and those who helped gather information.

"It means so much to us that so many people cared for Ralph and Kathy as friends and fellow cruisers that they are willing to stop and help in whatever way possible," the couple's sons, Bryan Hendry and Nick Buro, said.

Travel advisories near the Caribbean

Both Grenada and St. Vincent and the Grenadines are listed under a Level 1 travel advisory, according to the U.S. State Department. A Level 1 travel advisory urges U.S. citizens to take normal precautions in the area.

Other Caribbean islands are more dangerous, with Level 2 and 3 advisories in effect for the Bahamas and Jamaica, respectively. The advisory for the Bahamas was issued last month, warning travelers to "exercise increased caution" due to crime in some areas.

A security alert posted by the U.S. Embassy in the Bahamas also advised U.S. citizens to be "aware that 18 murders have occurred in Nassau since the beginning of 2024." The alert warns that murders have occurred at all hours including in broad daylight on the streets.

Contributing: Gabe Hauari, USA TODAY; The Associated Press