Paul and Gail Casey. (Katherine Frey/The Washington Post)

BASED ON what they were told by D.C. police, Paul and Gail Casey buried their 33-year-old son thinking he had started an argument that turned violent and caused him to be knocked to the ground with fatal injuries. That was nearly six years ago. The upstate New York couple have since conducted their own investigation, and the results are striking. There is good reason to think that a rush to judgment in their son’s case led to a wrong result. Officials have reclassified the death — it is no longer deemed “justifiable” — and police are pressing federal prosecutors to review the case. Justice demands that the request be seriously considered.

According to police, the death of Patrick Casey, an Army veteran who had served in Afghanistan and was in an international studies program at George Washington University, is open and is still actively being investigated. Casey died Sept. 27, 2011, of massive brain trauma, four days after he was involved in an early-morning altercation outside a McDonald’s in Georgetown.

At a news conference three days after Casey’s death, police said he had been drinking and acting in an annoying manner and may have instigated the physical confrontation. In November 2011, the U.S. Attorney’s Office told police that charges would not be pursued against three men involved in the fight, classifying the homicide as “justifiable” and “consistent with an individual acting in defense of another.”

Casey’s parents have since obtained police files through the Freedom of Information Act. Their investigation also includes analysis of surveillance video and depositions taken in civil suits against the three men involved in the fight. It all points to missteps in the investigation and inconsistencies in the accounts of the men. One witness said Casey was punched from behind. The man who was identified by authorities as striking the blow that resulted in Casey’s death was arrested three years later for assaulting a bouncer at a D.C. bar and entered into an agreement that deferred prosecution in exchange for community service.

Presented with this new material, federal prosecutors said they still weren’t going to prosecute in Casey’s death but this time cited “insufficient evidence . . . to meet the government’s burden to rebut a claim of self-defense or defense of another.”

Such reclassification is unusual, particularly after so many years, and the Caseys see it as a vindication of their son. But they believe the process was short-circuited, with no one ever held to account. Police Chief Peter Newsham told us he wrote directly to the U.S. attorney asking for further review. That office is soon slated for a change in administration. We hope the new U.S. attorney takes a fresh look at a case that demands better answers.