Yes, the name is Gunnery Sergeant Hartman and he died of gangrene in the movie full metal jacket. But in the actual story of Sergeant Gary L. Miller was found guilty by a jury for the murder of Gunny Hartman on charges ranging from negligent homicide to second-degree murder. There were no eyewitnesses present at the time and all available evidence pointed to Miller being guilty as charged but because it was a military court, it couldn't sentence him beyond 10 years so he's free as of today.