Jack Mannix was a high ranking Company operative within the FBI agency and a FBI special agent in charged of the undercover operations of the Company, he appeared in the video game adaptation of the first season of Prison Break.
Jack Mannix's character according to official site Jack Mannix's family emigrated to the US in 1973. Severing all ties with his few childhood friends back in Ireland proved to be a traumatic experience for the young and introverted Jack. Alone and friendless, he was subjected to his father Jack Mannix's father continual sexual abuses, which further scarred his psyche.
His stubborn nature pushed him to fight on and deny what happens during his youngness. After finishing law studies he enrolled into FBI Academy in Quantico and barely gratuated. Owing to his stubborn nautre and lack of intellect he was soon shuffled at a desk job into the FBI offices in Chicago.
Extremely dissatisfied, he began selling information to various clients (including the Abruzzi's mob which he was under the payroll and he betrayed) about the FBI's activities but he was soon red-handed and suspended from the FBI. Soon after his suspension from the Bureau he was quickly approached by The Company which was headhunting disgruntled government officials. His considerable experience helped him earn the job but he has always been careful to keep his "extracurricular activites" hidden from his colleagues.
Prison Break - The Conspiracy
As a senior Company operative Mannix is aware of the fact that the incarceration and execution of Lincoln Burrows is just a plan to make showing up Aldo Burrows from his hiding. He's given the charge of an undercover mission in Fox River after the Secret Service has discovered that Michael Scofield is incarcerated in the same prison as the guy who killed the VP's brother: Lincoln Burrows.
Mannix then summoned one of the best agent of the Company, Tom Paxton, at his office in the FBI building in Chicago. Mannix choose Paxton because he's a very effective agent and because he know too much about his links with the Abruzzi's mob and he must take him out of his business. During Tom's mission Mannix is his direct supervisor and report the last news about Michael and Lincoln, soon enough Mannix understand that Scofield and his brother are breaking out and he take the opportunity to kill both Burrows and Paxton.
Then he send, secretly, another operative named "Turk" to kill them both during the prison's riot, but the hit failed when Burrows killed accidently Turk. Mannix superiors, have realized that Agent Paxton is ineffective and eventually turned coat, send him (like Paxton) in the Fox River State Penitentiary to eliminate Burrows and Paxton. Unfortunately he meet his former "partner" mob boss John Abruzzi returning in Fox River after T-Bag's assassination attempt and Abruzzi warned him that both of him and Paxton are dead men. Tom discovers that Mannix and the Company has blackmailed the C.O Jones, in charge of the SHU (his daughter has been kidnapped by Company operatives) in the objective of murdering Burrows silently, but Mannix is intercepted by Paxton and the two are interrupted before they managed to fight against each other: Mannix fly with Paxton's little dictaphone.
He quickly get informed and discovered the hole in Michael's cell and the date of his escape. The day of the escape Mannix followed the Fox River Seven in order to kill Burrows but Paxton tracked him down in the sewers and engaged a hand fight woth Mannix but his last escape on the roof and engage a violent and bloody fight with Paxton disguised as a C.O. while Scofield and Burrows are passing the wall of the penitentiary. Mannix is targeted by a SWAT sniper in a C.P.D helicopter thinking that a prisoner (Mannix) is beating a C.O (Paxton) but cannot take the shot because the two are too close. The fight is very brutal but Paxton get advantage and push Mannix to the limits of the roof allowing Police Officer Harris to take a shot and killed Mannix by a single bullet and falling from the roof already dead.
Paxton did recover his dictaphone on his body before leaving the prison. Harris (the one who shot him), Moore and other Corrections Officers came to his body.
Personality and Traits
Jack Mannix is depicted as a tall and blond man with a loudy Irish accent, according to his Company files he was sexually assaulted by his own father and this events cause a trauma in Mannix psyche. During all his life his stubborn nature help him to resolve his problem and going ahead in the life. After gratuade from Law school he enrolled in the FBI not because of fighting the criminality but by patriotism and lust of money. During his time in the FBI he was assigned to dead end desk job because of his lack of intellect and became corrupted by the money of mob boss John Abruzzi. Angry, partiotic and frustrated Mannix was soon recruit by a shadow organisation, The Company. He became one of his valuable asset and was in charge of his undercover operations in the east coast but his lust of money keep him to sold information on the federal activities to the mob. He's depicted as a cold man who think that all he's doing is for the best of the Company and his country, despite his age (49 years) he seems to be a very deadly hand to hand fighter notably against operative Tom Paxton who's younger than him.