The report by the International Criminal Tribunal for the Former Yugoslavia said that it found, "simply no evidence of the necessary crime base for charges of genocide or crimes against humanity."
The tribunal's decision not to conduct a criminal investigation of NATO was announced June 2, and, according to the tribunal, "it is not the Prosecutor's normal policy to make public the details about investigations."
However, because NATO doesn't have the privacy concerns an individual might, and due to the amount of public debate about the tribunal's decision, a press release dated Tuesday said, "the Prosecutor considers that in this situation, quite unforeseen when the Tribunal came into existence, she should take the unusual step of making her reasoning public."
Joining the debate last week was Amnesty International, a worldwide human rights group, which claimed in a report titled Collateral Damage "that NATO did not always meet its legal obligations in selecting targets and in choosing means and methods of attack."
Amnesty specifically cited the bombing of the Serbian state television and radio station, in which 16 civilians died.
The International Tribunal's report examines a range of allegations made against NATO, which bombed targets in Kosovo and Serbia proper from March 24 to June 9 of last year.
The probe began in May 1999 after the tribunal received complaints from several sources, including academics, lawyers for Yugoslavia, and a committee of the Russian Parliament.
Led by prosecutor Carla Del Ponte, the investigation involved an " extensive review" of the evidence.
However, the investigating committee did not interview "those involved in directing or carrying out the bombing campaign" which claimed 495 civilian lives and wounded another 820 civilians, according to the tribunal.
On accusations the alliance's bombing campaign harmed the environment, the prosecutor found that, "The NATO bombing campaign did cause some damage to the environment," including the release of chemicals from chemical plants that were bombed.
But it also states that the U.S. and France haven't ratified the international laws that would cover such damage and that the damage didn't meet the law's standard anyway.
NATO was also accused on violating law by using depleted uranium in its bombs.
On this point the tribunal cites "the uncertain state of development of the legal standards governing this area." On the alliance's use of cluster bombs, the report concludes that there "is no specifitreaty provision which prohibits or restricts the use of cluster bombs."
In both cases, the report also states that the use of depleted uranium or cluster bombs in Kosovo did not appear to break any other international laws.
"NATO has admitted that mistakes did occur during the bombing campaign; errors of judgment may also have occurred," the tribunal says in its closing. "On the basis of the information reviewed, however, the committee is of the opinion that neither an in-depth investigation related to the bombing campaign as a whole nor investigations related to specific incidents are justified."
It is not clear if the release of the investigators' report will silence critics of the tribunal.
Immediately after the tribunal announced it would not conduct a criminal investigation of NATO, Russia's foreign ministry slammed the decision.
"It is far from being the first time that the tribunal has closed its eyes to cases where the norms of international humanitarian law have been violated by other participants in the conflict," the Foreign Ministry said in a statement.
"In this way, the court demonstrates its political prejudices. Such an approach does not contribute to a political settlement in the region, to the triumph of justice and the punishment of all those guilty," it said.
By JARRETT MURPHY