Jeffrey Deskovic, who spent half his life in prison for a crime he didn't commit, took the stand in White Plains Federal Court Monday.

For the first time, Deskovic told a jury about the false confession he made about murdering his classmate Angela Correa in 1989. He also discussed the role now-retired Putnam County investigator Daniel Stephens played.

Deskovic claims Stephens aggressively interrogated him when administering a lie detector test to get him to admit to rape and murder.

"If he hadn't done what he did, I would not have falsely confessed." Deskovic testified. "I consider Mr. Stephens most culpable."

Deskovic testified that he sat in a small room with the door closed for 6 1/2 hours attached to a polygraph machine. He says he had nothing to eat and only drank coffee.

Deskovic told jurors he took the polygraph test because he naively thought it would help Peekskill police with their investigation. Instead, the false confession led to 16 1/2 years in prison until DNA exonerated him.

He is is expected to resume his testimony again Tuesday.