Raymond A. Davis is a U.S. government employee or contractor now in police custody in Pakistan in connection with the shooting of two men in Lahore on January 27. The State Department has asserted diplomatic immunity on Davis’s behalf, and Senator John Kerry has rushed to Pakistan to attempt to win his freedom. Pakistani courts and authorities are challenging the claim of immunity, though President Asif Ali Zardari is siding with the State Department.

According to Washington, the matter is simple: Davis carries a diplomatic passport and therefore has immunity. However, anyone schooled in the law of diplomacy knows that the State Department is playing fast and loose with the law. The issuance of a black passport does not confer diplomatic immunity in such circumstances; that step requires the recognition by the host state of diplomatic status. And the picture surrounding Mr. Davis is exceedingly murky. The New York Times discreetly reports facts that have been sensationalized in the Pakistani media:

American officials said that two armed men threatened Mr. Davis when he was driving alone on a busy Lahore road, and that he fired in self-defense. The statement on Friday night said that Mr. Davis was assigned as an “administrative and technical” member of the staff at the American Embassy in Islamabad. But his exact duties have not been explained, and the reason he was driving alone with a Glock handgun, a pocket telescope and GPS equipment has fueled speculation in the Pakistani news media.

David Lindorff has probed a bit more deeply into the story:

Davis (whose identity was first denied and later confirmed by the US Embassy in Islamabad) and the embassy have claimed that he was hired as an employee of a US security company called Hyperion Protective Consultants, LLC, which was said to be located at 5100 North Lane in Orlando, Florida. Business cards for Hyperion were found on Davis by arresting officers…

First, there is not and never has been any such company located at the 5100 North Lane address. It is only an empty storefront, with empty shelves along one wall and an empty counter on the opposite wall, with just a lone used Coke cup sitting on it. A leasing agency sign is on the window. A receptionist at the IB Green & Associates rental agency located in Leesburg, Florida, said that her agency, which handles the property, part of a desolate-looking strip mall of mostly empty storefronts, has never leased to a Hyperion Protective Consultants. She added, “In fact, until recently, we had for several years occupied that address ourselves.”

Nothing about Davis’s background would suggest that he is qualified to serve as a diplomatic or consular officer, either. To the contrary, the evidence suggests that Davis, a former Special Forces member, was working in an extremely shadowy area of security and intelligence gathering. He may be engaged in valiant and high-risk service to his country, but he is performing it in circumstances that afford little legal protection.

The State Department does routinely furnish diplomatic cover for such operatives in an effort to facilitate their work. But as the Abu Omar prosecution in Milan shows, the United States is often hesitant to invoke diplomatic immunity in such cases because some kinds of intelligence operations are inconsistent with diplomatic duties, attempts to invoke immunity may not be recognized by foreign prosecutors and foreign courts, and the effort may undermine the protections afforded legitimate diplomats.

The Davis case raises another painful issue for the United States. In order to secure Davis’s freedom, Senator Kerry and Secretary Clinton need to be able to argue to their Pakistani counterparts that the United States is capable of investigating the Lahore incident fairly and taking criminal or disciplinary action as appropriate. Davis claims he acted in self defense, attempting to stop a daytime robbery. The use of lethal force in such circumstances may well be justified. That’s the sort of call that a prosecutor would normally make after a thorough investigation.

The problem is that America’s track record shows clearly that it doesn’t investigate or act on claims involving either intelligence agents or contractors. As I noted in earlier Congressional testimony, the United States has a de facto policy of impunity for its security contractors and agents who kill or injure foreign civilians. Notwithstanding promises by both the Bush and Obama Administrations to address this problem, there has been no real progress. Moreover prosecutions showcased by the Justice Department as a demonstration of their seriousness fizzled into nothing in the courts—including the high-profile case involving the shooting of 17 Iraqi civilians in Nisoor Square in 2007. Pakistani authorities would therefore be correct to dismiss any claims by American diplomats that someone like Davis would be fairly investigated and, if appropriate, prosecuted. There is no real prospect of either.