David Rosen was an Assistant U.S. Attorney who lost his job after the Defiance scandal was killed. He is a stickler for justice and is now the US Attorney for the District of Columbia.

David was an up-and-coming Assistant U.S. Attorney in the U.S. Attorney's office until he lost the biggest case of his career, the prosecution of Lindsay Dwyer. He lost because his frenemy called in a favor to "fix" the case by having it acquitted.

David is a stickler for justice and does not approve of Olivia Pope's methods but they are still friends. He doesn't stop until he gets justice for a victim and/or brings the person responsible for any crime brought to justice.

David is in relationship with Abby, i.e. one of Olivia's gladiators. David and Abby's relationship sparked up when he was on his witch hunt out to get Olivia. Knowing he needed to get to someone on the inside of OPA he sparked up a conversation with Abby in bar and they wound up in bed together.