By his own count, Dr. Cyril H. Wecht, one of the nation’s foremost forensic pathologists, has testified in more than 1,000 civil and criminal trials in his 46-year career, and opined on thousands more on television, on radio and in print.

But now, for the second time in his life, Dr. Wecht is the accused.

In a case Congressional Democrats say is a politically motivated prosecution by a Republican administration, Dr. Wecht, a Democrat, is in federal court here facing 41 criminal counts. Opening statements are scheduled to begin Monday.

Those counts include mail fraud, wire fraud and theft of honest services. The most serious charges could send him to prison for up to 20 years per count.