He Went Out for Cigarettes. A Decade Later, His Car Was Found in a Pond.

One morning in late December 2013, Donald L. Erwin, a 59-year-old disabled veteran, told his wife he was going to buy cigarettes.

He often woke before dawn and was a heavy smoker. She went back to sleep. Sometime after 6 a.m., Mr. Erwin got into his silver Hyundai and left his mobile home in the central Ozarks.

He never returned.

For nearly a decade, Mr. Erwin’s family, together with some friends and locals, have scoured the lakes and valleys of the hilly region near his home in Camdenton, Mo., for clues. “I did not stop for nine years,” Mr. Erwin’s sister, Yvonne Erwin-Bowen, said in an interview, noting that she would travel from her home in Kansas City at least twice a year to search. Mr. Erwin’s wife has since passed away.

By last year, Ms. Erwin-Bowen, 62, had begun to lose steam. “I didn’t go look for my brother one time,” she said. “I literally put it in God’s hands.”

Then, last month, Ms. Erwin-Bowen received a call from a friend: A scuba diver had found her brother’s car about five miles from his home, submerged in a pond. The car, a 2002 Elantra, was retrieved on Dec. 16 from a private property in southern Camden County, according to a news release from the local authorities. Several days later, detectives and cadaver dogs recovered human remains and an artificial hip that matched Mr. Erwin’s, the authorities said.

The diver, James Hinkle, said in an interview that he became aware of the case about two years ago and began methodically searching bodies of water near Mr. Erwin’s home in a kayak mounted with sonar equipment, as well as with a drone.

On the afternoon of Dec. 14, Mr. Hinkle, whose volunteer scuba search-and-recovery team runs a YouTube channel, decided to search a pond on a private property, when he noticed a tire floating in the water. “That kind of got my nerves a’ jumping,” he said. Using a drone, Mr. Hinkle then observed a light, square-shaped object in the water. As he began to move the drone closer, he added, “it looked more and more like a car.”

Two days later, Mr. Hinkle returned to the property with his kayak, a submergible camera and a magnet tied to a rope, which he dropped onto the car as a guide. Sheriff’s deputies and detectives, together with divers from the local fire department, were able to reach the car and match its license plate to Mr. Erwin’s. A local towing company then helped haul the vehicle from the pond.

The grim discovery has brought a confusing mix of closure, elation and renewed agony to the people who spent years searching for Mr. Erwin. “It is a new heartbreak,” Ms. Erwin-Bowen, his sister, said. “Even though I knew in my heart he was gone — accepting the reality is a whole different thing.”

Mr. Erwin, who was also known as “Donnie,” served in the Navy during the Vietnam War and later moved to Georgia, she said. But a rare condition led to his losing a leg. Ultimately, Mr. Erwin lost his job as a programmer at Mitsubishi, she said.

Eventually, Mr. Erwin, his wife and son moved to a mobile home in the Ozarks. Shortly before Mr. Erwin’s death, he learned he would likely need to have his second leg amputated, Ms. Erwin-Bowen said. “My brother did what he did because he didn’t want to be a burden on anybody,” she added, noting that she believed he had taken his own life.

“People always say when you find that loved one, you get the closure,” she added. “No you don’t, because you’ll never understand.”

More than 24,000 people remain missing across the United States, according to the National Missing and Unidentified Persons System. Other cold cases have been solved by amateurs before the authorities. In 2021, a YouTuber found a car belonging to two Tennessee teenagers who had been missing for 21 years; another search-and-recovery dive group claims it has helped solve 29 such cases.

Ms. Erwin-Bowen said that she hoped that her family’s story would encourage others in similar situations not to lose hope. “Never stop looking, the answer is out there,” she said. “Never give up.”