THERE IS, at this stage, no reason to doubt the official account of the slaying Wednesday of Rigoberto Alpizar by federal air marshals in Miami. According to the government, Mr. Alpizar, a U.S. citizen on his way from Ecuador to Orlando, left his seat as boarding was ending in Miami and shouted that he had a bomb in his carry-on luggage. When two marshals on the flight ordered him to stop, he ran from the plane onto the jetway. The officers followed and, in the jetway, shot him when he allegedly reached into his bag and began moving back toward them.
If all this is true, the marshals acted reasonably, though Mr. Alpizar's luggage proved to contain no bomb. Someone who announces he has a bomb must be presumed to be telling the truth when other lives are at stake, and in hot pursuit of a possible terrorist, officers are entitled to use deadly force when such a person reaches into a bag instead of following a command to get down.
Yet the matter requires a thorough and independent investigation. For the air marshals, in fact, did not stop a bombing. Though they may have been justified, they killed an American who appears to have no connection to terrorism. According to eyewitness reports, Mr. Alpizar's wife tried to explain that he was mentally ill and had not taken his medication. For the air marshals program to have credibility, it is essential for the public to have more than the government's word that the killing of such a person was really necessary, not an overreaction to an ill person who posed no threat.
When British police killed a Brazilian named Jean Charles de Menezes this year in the London Underground, the shooting initially appeared to be a reasonable hot-pursuit killing of a possible terrorist. Mr. Menezes, police said, was wearing a heavy jacket in summer -- and it was widely reported that he vaulted over a turnstile and had run from police. None of this turned out to be true. He was wearing a light jacket, walked calmly through the turnstile and was being restrained by one officer when another shot him, it later emerged. It is essential that the air marshals not labor under public doubt concerning what happened here.
The Miami-Dade County Police Department is investigating the shooting. Federal officials have pledged full cooperation, though they have also gone out of their way to prejudge the matter and declare that the officers in question acted reasonably. This is premature. Any time a government officer takes someone's life, judgment ought to wait until the facts become clear.