The 22-year-old case was most unusual even for Dr. Robert H. Kirschner, forensic pathologist. Last August, the retired deputy chief medical examiner for Cook County, IL, provided his expert opinion in the murder trial of a man who had killed his girlfriend, buried her under a tree, and then claimed she was among the passengers who perished in the fiery crash of American Airlines flight 191 on May 25, 1979.

Back in 1979, Dr. Kirschner helped to identify the remains of the 273 people killed in what was – until the September 2001's terrorist attacks – the worst air disaster in American history. Now he was called to testify that the defendant's girlfriend was not incinerated in the crash.

Although 29 of the crash victims could not be identified, Kirschner told the court that the missing girlfriend was not one of them. She was in her fifth month of pregnancy when she disappeared, and there were no pregnant women among the unidentified crash victims.

When the defense lawyer had his opportunity to cross-examine, all he said was, "No questions, your Honor."

"He did not want to be beaten up by Dr. Kirschner in front of the jury," explains Mark Blumer, Michigan's first assistant attorney general. Blumer won the murder conviction, even though the victim's body was never found.

Kirschner is a formidable expert witness that lawyers don't want to face on the opposing side. As a forensic pathologist, he has testified in more than 600 state and federal court cases throughout the US. He worked for 17 years, first as a deputy medical examiner and then as deputy chief medical examiner for Cook County (which includes the city of Chicago). But that was only his day job.

In his spare time, Kirschner visited many of the world's "killing fields," to help the dead there bear witness. In more than a dozen countries in Central and South America, Europe, Africa, Asia, and the Middle East, he has used the tools of science and medicine to help expose state-sponsored murders, torture, and other rights abuses.

In Shakespeare's Julius Caesar, Marc Antony shows his fellow Romans the dagger wounds in Caesar's body and wishes that he could "put a tongue in every wound" that would move Rome to avenge Caesar's assassination.

For more than 15 years, Kirschner has put such tongues in the wounds of thousands of victims of state-sanctioned murder around the world. He has become, in the words of the famous New York medical examiner Dr. Michael Baden, "the conscience of forensic pathology."

In 1995, Kirschner founded the International Forensic Program of Physicians for Human Rights. As the program's director until 1998, he led the exhumation of numerous mass graves on beh