Theranos Lab Director Revealed as Key Source for WSJ Expose (3)

A former lab director at Theranos Inc. who is testifying against Elizabeth Holmes at her criminal fraud trial revealed that he was a source for the Wall Street Journal reporter whose stories led to the collapse of the blood-testing startup.

Adam Rosendorff has said he resigned from the company in late 2014 because he found Holmes unwilling to address quality-control problems with Theranos machines. He testified Tuesday that he later received a phone call from Journal reporter John Carreyrou and agreed to speak with the journalist off the record.

“I felt obligated to alert the public,” Rosendorff told jurors. “I ...