- "We're moving all agents below level five to East holding. I have men monitoring microphones placed in most of the rooms."
"And our strike team?"
"Has stormed the plane, yes."
- ―Jacobson and Victoria Hand
Jacobson was a S.H.I.E.L.D. agent assigned to the Hub. During the HYDRA Uprising he worked with Victoria Hand to maintain the security of the Hub against HYDRA. While transporting the HYDRA infiltrator, John Garrett also known as the Clairvoyant, Jacobson was murdered by HYDRA sleeper agent Grant Ward.
Agent of S.H.I.E.L.D.
When the HYDRA infiltration of S.H.I.E.L.D. was discovered, Agent Jacobson was one of five other agents that Victoria Hand knew was not a sleeper agent. Agent Jacobson was in the Hub when Hand gave the order to kill Coulson's Team and Agent John Garrett since she believed they were traitors.
When Victoria Hand wanted to prove to Jemma Simmons that Phil Coulson was a HYDRA agent, she asked Agent Jacobson to list Coulson's "crimes" against S.H.I.E.L.D. He gave a list of the various exploits that Coulson's team had, including not reporting on Akela Amador.
After Coulson's team arrived and Garrett's treason was revealed, Garrett was to be transported to the Fridge by Agents Jacobson, Chaimson, Hand and Grant Ward. En route, Hand asked Ward to kill Garrett, so as to eliminate his threat. Instead, Ward shot and killed Hand, Chaimson and Jacobson. The S.H.I.E.L.D. agents died as Ward and Garrett went on to go about HYDRA's new agenda, showing their true colors.
- S.H.I.E.L.D. (First Incarnation)