West Beach of Koh Tang in September 2012, 37 years after U.S. Marines landed here and fought entrenched Khmer Rouge guerrillas in what would be the last battle of the Vietnam War. Thirty-eight American servicemembers died in aircraft mishaps and fighting and at least three were left behind and executed in an effort to rescue the crew of a kidnapped U.S. merchant vessel, the SS Mayaguez. (Matthew M. Burke/Stars and Stripes)

East Beach of Koh Tang in September 2012, 37 years after U.S. Marines landed here and fought entrenched Khmer Rouge guerrillas in what would be the last battle of the Vietnam War. Thirty-eight American servicemembers died in aircraft mishaps and fighting and at least three were left behind and executed in an effort to rescue the crew of a kidnapped U.S. merchant vessel, the SS Mayaguez. East Beach was the scene of two helicopter crashes and heavy loss of American lives. (Matthew M. Burke/Stars and Stripes)

Lance Cpl. Joseph Hargrove was one of at least three Marines left behind on Koh Tang following the battle between the U.S. and communist guerrillas from the Cambodian Khmer Rouge in May 1975. The Khmer Rouge commander of the island, Em Son, said that he executed the 24-year-old about a week after the battle after Hargrove was caught stealing food and then tried to escape. (Photo courtesy of Cary Turner)

Pfc. Gary Hall was one of at least three Marines left behind on Koh Tang following the battle between the U.S. and communist guerrillas from the Cambodian Khmer Rouge in May 1975. The Khmer Rouge commander of the island, Em Son, said that Hall was caught about a week after the battle with Pvt. Danny Marshall and taken to the mainland of Sihanoukville and Wat Inn Nhean, a temple turned Khmer Rouge prison. Hall was later executed and his body dumped at a beach called Koh Puos, or Snake Island. After he kept washing up on shore, Son instructed his troops to pull the body into some rocks on shore. (Photo courtesy of www.mayaguezfallenheroes.com)

Pvt. Danny Marshall was one of at least three Marines left behind on Koh Tang following the battle between the U.S. and communist guerrillas from the Cambodian Khmer Rouge in May 1975. The Khmer Rouge commander of the island, Em Son, said that Marshall was caught about a week after the battle with Pfc. Gary Hall and taken to the mainland of Sihanoukville and Wat Inn Nhean, a temple turned Khmer Rouge prison. Marshall was later executed at a place called Dom Ak Sdach, or the King's Place. Son said that he found Marshall's battered body and ordered him buried. (Photo courtesy of www.mayaguezfallenheroes.com)

The former Khmer Rouge command building where Em Son said that Lance Cpl. Joseph Hargrove was captured in the wee morning hours trying to steal food, about a week after the May 15, 1975 battle between U.S. servicemembers and communist guerrillas. (Matthew M. Burke/Stars and Stripes)

Stakes placed by investigators from the Joint POW/MIA Accounting Command mark the spot on Koh Tang island where a body was recovered during past excavations. Former Khmer Rouge commander Em Son said that this is the spot where he had Lance Cpl. Joseph Hargrove buried after he executed him in 1975. JPAC has said they they recovered remains at the site but that they did not find Hargrove. (Matthew M. Burke/Stars and Stripes)

The SS Mayaguez on May 15, 1975. (Photo courtesy of the National Museum of the U.S. Air Force)

The Wat Inn Nhean temple complex in Sihanoukville, Cambodia, has returned to a place of peace today after it was used as a Khmer Rouge prison in 1975. Pfc. Gary Hall and Pvt. Danny Marshall were reportedly held here after they were captured on Koh Tang island and taken to the mainland. The cells were located on the ground level of the building on the right, according to Cambodian sources. With food scarce and no relations between the communist regime and the U.S. government, the Khmer Rouge decided to execute the pair of Marines, sources said. They were killed nearby. (Matthew M. Burke/Stars and Stripes)

Pvt. Danny Marshall was taken to Dom Ak Sdach, or the King's Place, in Sihanoukville, Cambodia, and was executed by being beaten to death between these two palm trees, Cambodian sources said. He was then buried here, but the Khmer Rouge later bulldozed the site to make way for development. Officials from the Joint POW/MIA Accounting Command confirmed that they had excavated the site and removed remains from here in 1999 but said those results are not available. Marshall is still listed as unaccounted for. (Matthew M. Burke/Stars and Stripes)

Pfc. Gary Hall was taken to Koh Puos, or Snake Island, on the mainland in Sihanoukville, Cambodia, and beaten to death here by the beach, Cambodian sources said. His body kept washing up on shore, so the Khmer Rouge tied a rope around him and pulled him in between these rocks. Officials from the Joint POW/MIA Accounting Command confirmed that they had excavated the site and removed remains from here in 1999 but said those results are not available. Hall is still listed as unaccounted for. (Matthew M. Burke/Stars and Stripes)

The body of Marine Ashton Loney lies on West Beach covered in a poncho after he was killed in action during the battle of Koh Tang. This photograph was taken by Marine Fred Morris during a lull in the fighting. Loney remains unaccounted for after his body was left behind during the confusion of the evacuation and fighting. (Photo courtesy of Fred Morris)

Today, Em Son, 63, lives in the remote jungle near the border with Thailand with many other former Khmer Rouge soldiers and officials. He claims to have executed Lance Cpl. Joseph Hargrove despite previous statements to the contrary and to having shot down Knife 31 on the East Beach with a rocket, resulting in heavy loss of American life. In recent years, Son has worked with American officials to repatriate the missing from Koh Tang and said that Hargrove's body has been recovered. (Matthew M. Burke/Stars and Stripes)