ROSS TOWNSHIP, Mich. » Seven decades after a teenage U.S. Marine fell in combat in World War II, the Detroit native finally is back home, thanks to scientific advancements than made identifying his remains possible.

A burial ceremony with full military honors took place Monday for Robert McConachie at Fort Custer National Cemetery, west of Battle Creek in Kalamazoo County’s Ross Township.

"Growing up I knew a little of my uncle," his nephew, Col. Andrew McConachie, told WWMT-TV. "But today allows us to know him better."

Robert McConachie, 18, fell in heavy fighting on the Japanese island of Okinawa. He was reported killed in action in June 14, 1945, during a battle on Kunishi Ridge.

His remains were brought in 1987 to the Army’s Central Identification Laboratory at Hawaii’s Joint Base Pearl Harbor-Hickam. They remained unidentified for decades, but developments in testing using mitochondrial DNA recently helped the Pentagon link them to his brother.

Besides the strands of DNA within a cell nucleus, genetic material also is found within cell structures known as mitochondria. That material can be used to make family connections.

"The case was re-examined in 2010 by … analysts to identify possible individuals who were unaccounted for from this battle and to facilitate family reference sample collection," according to the Department of Defense’s Prisoner of War/Missing Personnel Office. The DNA, plus dental records, then made a positive ID possible, the Pentagon said.

McConachie was only 17 when he enlisted in the Marines in 1944, and James McConachie had to sign a waiver for his son because of his age.

"Today’s service was more than just family and friends remembering my uncle," Andrew McConachie said. "It was really the nation honoring the fallen."