Brown, the author whose of the bestseller that has been adapted by Hollywood and scheduled to hit theaters in May, has denied plagiarizing "The Holy Blood and the Holy Grail" by Michael Baigent and Richard Leigh.
The two authors sued Random House, which published both books centering on a theme of what would have happened if Jesus and Mary Magdalene had a child.
Brown testified the non-fiction book by Baigent and Leigh was one of several sources he consulted while writing "The Da Vinci Code," but he did not copy it.
During his closing arguments, the attorney for the plaintiff's warned Brown's testimony should be considered with "deep suspicion," the BBC said.
A verdict is expected by April 13.