In September 1999, Michael J. Mahoney, a master sergeant in the U.S. Air Force stationed at Lackland Air Force in San Antonio, Texas, tested positive for cocaine during a routine random urinalysis.
Mahoney went on trial in a general court-martial court in April, 2000. The prosecution called Dr. Philip L. Mobley III, the laboratory certifying official at the Air Force Drug Testing Lab at Brooks Air Force Base in San Antonio, as an expert on urinalysis. Mobley testified to the integrity of the testing process as well as the procedures followed.
Mahoney’s attorneys presented no defense evidence, focusing their case on attacking the credibility of the testing program. On April 21, the jury convicted Mahoney. He was sentenced to a bad-conduct discharge, loss of six months pay and a reduction in grade.
After the trial, Mahoney’s defense attorneys learned of a letter criticizing Mobley’s job performance and outlining how Mobley had showed “an obvious lack of enthusiasm or conviction about the Air Force’s drug testing program.”
Because Mobley had testified glowingly about the program in Mahoney’s trial, the defense argued on appeal that the failure of the prosecution to disclose the document had undercut their ability to challenge Mobley during cross-examination.
On June 25, 2003, the U.S. Court of Appeals for the Armed Forces reversed Mahoney’s conviction, ruling that the prosecution had failed to turn over impeachment evidence to Mahoney’s defense lawyers.
The court found that Mobley may have given his positive testimony at Mahoney’s trial because he was hoping to receive favorable work evaluations and keep his job in light of the letter criticizing his work in other trials.
“Cross-examining Dr. Mobley about the letter may have revealed this motive, serving to damage Dr. Mobley’s credibility, and thereby enhance the defense’s case,” the court said.
After the reversal, the case was dismissed, the bad-conduct discharge was erased and Mahoney received back pay and his grade was restored.
– Maurice Possley