What was the result of the first polygraph test?

The first polygraph was invented in 1917 and was used for counterintelligence work during World War I. In 1938, the FBI began using polygraph examinations. The first polygraph to be used in a courtroom as evidence was on Dr. Francis Sweeney; a chief suspect in the Cleveland torso murders. He failed the polygraph test but was released later due to lack of evidence.