Bill and Thomas, you were on the right track, but Laurie is correct. The strange thing about Dr. Lewis' statement is he got David Herold's first name wrong. He wrote a letter "asking for the body of James Herold to be returned to the family to comfort them and to give Herold a Christian burial." Andrew Johnson acted upon the request and also called Herold by the wrong first name in his response to Lewis.
SOURCE: Joan Chaconas' research as published in the article entitled "What's In A Name" in the Surratt Courier.