Jacob Jackson was a former sergeant of the Los Santos Police Department.
On May 9th, Jacob approached Gunnar Mason, who was put up for adoption as a young child; Jackson was born in Los Santos as well and adopted by an Australian family, while Mason was never adopted and instead grew up in foster care. Jackson presented Mason with a nearly identical childhood drawing to his own, except Jackson's included a brother in the scene. Jackson revealed that he thought he and Mason were brothers and a DNA test revealed that Mason and Jackson were a 99.8% genetic match as siblings. In the past, people had commented on Jackson and Mason's similar appearance and the two bonded over their eerily similar backgrounds.
As of May 11th, 2018 Jacob has been made a full trooper by Mason. After a short final evaluation, where Mason's only comment was to 'improve his driving', he was promoted.
Jacob was hospitalized on May 31st 2018, when serial killer Jasper Elliot took Jacob as a hostage and demanded $50k in return for his life. After Jackson attempted to reach for his panic button while still held hostage, Jasper slit his throat and fled. Jackson was taken to ICU but survived the attempt itself and was back on duty by June 2nd.
Trooper Jackson briefly returned to active duty when Grove Street Apartments were raided by the SASP on November 9th 2018.
As of July 1st, the San Andreas State Police has split into three separate departments, causing all former troopers to be reassigned to different departments.