Jacobson most likely had a background in either military, law enforcement or some other security based profession before joininf the Westworld QA Security Force.
Jacobson was seen working at the Sector 19 Remote Refurbishment Facility when Blaine Bellamy burst in and told them that the Hosts had broken their programming and were killing people. He was followed into the facility by Dolores Abernathy, Teddy Flood, and Angela. Jacobson was taken hostage by Dolores, and tortured for information on the Delos response to critical failure in the park. His head was repeated dunked in the goo that Host were created from, which burned him, and Jacobson informed Dolores that the response would be around 800 personnel clearing each sector at a time, and gave her the location of their initial arrival point.
Jacobson was dragged by Clementine Pennyfeather to Fort Forlorn Hope. He's ordered to make a run for it, as Colonel Brigham tests a stolen P90. Brigham kills him.