Following the Račak massacre of 45 Kosovar Albanians in January 1999, Walker visited the site and called it an "unspeakable atrocity" and "crime very much against humanity." On January 18, 1999, the FR Yugoslavia government accused him of "going far beyond his mandate", and of "waging a campaign of disinformation against Serbia", declaring him persona non grata and ordering him to leave the country. A week later, on the intervention by European Council and Russian Federation, Prime Minister of FR Yugoslavia Momir Bulatović froze the decision. The Račak massacre was a pivotal incident in pushing NATO into launching its bombing campaign against Yugoslavia. The OSCE mission was discontinued following the end of the Kosovo War in June 1999. In a 2008 interview, Helena Ranta, the Finnish pathologist who was tasked with examining the Račak massacre, accused Walker of pressuring her into proclaiming that Serbian security forces were responsible for the massacre in her report, despite it not being a part of her job.