So says the Chronicle Review:

We talked to the teaching assistant for the course, who confirmed Mr. Bellesiles’s account of the student’s story. According to the teaching assistant, a Marine veteran, the student told him that his brother had been shot in the head and later died from his injuries.
The Chronicle also spoke with the student called “Ernesto” in the article. The student said the soldier who died was his half-brother, was a member of the U.S. Army, and had died in Afghanistan in November. The student declined to provide further details because of unspecified “issues.”
At The Chronicle’s request, an Army spokesman searched a database of all U.S. military deaths in Iraq and Afghanistan using the name the student provided. There were no matches. The Chronicle’s own search of Department of Defense news releases turned up no casualties under any name that matched the student’s description.
Subsequently the student told us that he had fabricated several details in the story he had told Mr. Bellesiles and The Chronicle. The student said he knew a soldier who he believed had died in Afghanistan, but he said the person was not his half-brother. The student had no explanation for why the name was not on the military’s casualty lists.