David Edgar Herold was an accomplice of John Wilkes Booth in the assassination of Abraham Lincoln. After guiding fellow conspirator Lewis Powell to the home of Secretary of State William H. Seward, whom Powell attempted to kill, Herold fled and met with Booth outside of Washington, D.C. They then proceeded to Surrattsville, Maryland where they picked up weapons that Mary Surratt had left earlier for them at her property. Wikipedia*
On the C-SPAN Networks:
David Herold has one video in the C-SPAN Video Library; the first appearance was a 1988 News Conference.