A federal judge found a longtime criminal defense lawyer in Washington guilty for his lead role in a scheme to fabricate evidence, a win for prosecutors in a closely watched case that raised concern in the defense bar.

The attorney, Charles Daum, was charged in a conspiracy to dupe jurors in a drug case in 2008 in U.S. District Court for the District of Columbia. Prosecutors alleged that Daum, working with two private investigators, presented staged photos to jurors to trick them into thinking that drugs belonged to his client’s brother.