Julian Assange avoided outing his source for the thousands of documents he released through Wikileaks this week, but military investigators believe they already have their man.  Bradley Manning, who gave Assange video of a 2007 helicopter attack in Baghdad that killed a reporter tagging along with insurgents, is the prime suspect for the latest document release as well.  The Wall Street Journal reports this morning that they have “concrete” links between Manning and the material:

A search of the computers used by Pfc. Manning yielded evidence he had downloaded the Afghanistan war logs, which span from 2004 until 2009, the official said. It’s not clear precisely what that evidence is.

The investigation is also looking at who might have helped Pfc. Manning provide the documents to WikiLeaks, a web-based group that earlier this week released 76,000 secret reports from Afghanistan.

Because of the focus on civilians who helped Pfc. Manning, the Federal Bureau of Investigation and the Justice Department have been brought into aid the investigation lead by the Army Criminal Investigation Command.

Defense officials are also combing through Pfc. Manning’s computers in a bid to figure out what other material he may have stolen as they try to anticipate what other material WikiLeaks may have.

WikiLeaks says it has at least 15,000 more Afghanistan documents the group withheld until some details could be redacted.

Assange claimed to have given the White House a warning weeks ago about the release of the documents, which he said the Obama administration ignored, according to Andrew Napolitano of Fox News.  Regardless, the exposure of the data and especially of hundreds of informants and aides in Afghanistan has put many lives at risk.  A heads-up to the White House does not mitigate in the least the crime of exposure, and at least the moral guilt of any deaths that occur as a result, if not legal guilt for Assange.

For Manning, the argument may be a lot less academic, mainly because the US has him in custody while Assange remains out of reach. If he participated in a conspiracy to steal classified material, that’s a felony with a long prison term attached.  Murders committed as a result of that felony could bring further charges against Manning, although it might be hard for a prosecutor to tie retaliation murders in Afghanistan to the specific release of information about their cooperation, especially considering the violent environment in Afghanistan anyway.

The release of information that puts soldiers directly at risk might make for a better case of treason, if the government chooses to pursue those rare charges.  It will be interesting to see how far prosecutors will go if they can tie Manning directly to this release.