Prior to the events of Arkham Knight, the militia were once stationed at a secret training facility somewhere in Venezuela where various mercenaries were gathered. The Arkham Knight had managed to gather and lead a large army of mercenaries from all over the world and used the secret facility to train them for the inevitable attack on Gotham City. Each of the mercenaries all had dark pasts and various backgrounds making the militia a very sophisticated and well trained organization and were prepared to kill Batman. Eventually, the militia was given over $3,000,000,000 by Scarecrow and were given advanced technology, brand new weapons, optic camouflage suits, new armor and gear, and even various unmanned tank drones, APCs, and aerial drones, and the militia soon became allies with Scarecrow's Army.
On the day of Halloween, Scarecrow unleashes a new fear toxin on a Gotham Diner and threatens to unleash it upon all of Gotham. This results in the entire civillian population being evacuated and the Militia to invade and occupy the entire city. The Militia soon assert their dominance by setting up checkpoints, patrols, watchtowers, and send out their drones to scour the city and kill Batman. Eventually, Batman comes face-to-face with the Militia and is able to overcome and devastate them despite their intense training. Militia forces are sent everywhere and eventually, Batman fights the Arkham Knight and is able to beat him. This results in Jason Todd going off the grid and Scarecrow soon places Deathstroke to be the commander of the Militia and he takes the position. Eventually however, Batman is able to beat the Militia and has all of the villains and militia commanders, lieutenants, and remaining soldiers thrown in jail, leaving the organization dissolved at the end.
At the end of the game, the militia has been fully dissolved as all of the surviving soldiers have been arrested. It is unknown whether or not any other militia members were able to escape Batman.
Those of American citizenship could well be charged with treason and others with terrorist activities. Also, given the animosity overheard by Batman from Gotham's more standard criminals, their stay in Gotham's jails was likely to be a very unpleasant one on many levels.
- Scarecrow - Benefactor. (formerly)
- Arkham Knight - Founder and Original Commander. (formerly)
- Deathstroke - Mercenary, Campaign Advisor, Second-in-Command, and Current Commander.
- Militia Commander - Sergeant and Higher-Ranking Non-Commissioned Commanding Officer who remotely controls all unmanned tank drones and aerial drones.
- APC Lieutenants - Senior Lieutenants, APC Drivers/HVPs, and Field Commanders.
- Militia Leader (Killinger Department Store in Drescher, Founder's Island) - High-Ranking Commanding Officer who wore the prototype explosive vest.
- Militia Leader (Ace Chemicals Processing Plant, Bleak Island) - High-Ranking Commanding Officer who was stationed at the ACE Chemicals Processing Plant on Bleake Island. (deceased)
- Personnel Ranks:
- Militia Soldiers - Foot Soldiers, and although they behave like any other henchmen, they communicate through radio, allowing them to respond faster to Batman's movements and actions in areas occupied by armed Militia soldiers.
- Medics - Medical Non-Combative Soldiers who revive and help wounded and/or unconscious Militia soldiers. They occasionally use their defibrillators to charge Militia soldiers' combat suits to carry electrical charges that render the soldiers invulnerable to Batman's attacks in melee combat.
- Combat Specialists - Ninja-Like Soldiers armed with swords and trained in advanced melee combat, and capable of dodging Batman's attacks, attack more quickly, although they behave identically to the League of Assassins Ninjas.
- Brute Weapon Experts - Large, Brutish, Heavily Armored, and Stronger Soldiers who occasionally use arm-mounted melee weapons, such as retractable blades, shields, and electromagnetic-gloves.
- Mini-Gunners - Brutes equipped with mini-guns.
- Checkpoint Commanders - Soldiers wearing beige armor placed in charge of the Militia's Checkpoints that are embedded all around Gotham, and operating them with remote controllers.
- Explosive Experts - Soldiers equipped with landmines and sticky mines used to prevent Batman from taking down anymore soldiers if he keeps on incapacitating them from behind stealthily while on the ground or grabbing them from above on vantage points before leaving them dangling too many times.
- Boa Sentry Drone Controllers - Stationary Soldiers who remotely pilot Boa Sentry Drones with remote controllers to patrol certain areas occupied by Militia soldiers equipped with firearms.
- Detective Mode Trackers - Vigilant Soldiers equipped with handheld devices that can pinpoint Batman's location by tracing, tracking, and identifying the signal his Detective Mode systems emits if used for too long.
- Detective Mode Jammers - Soldiers equipped with communications disruption backpacks capable of jamming Batman's Detective Mode vision when used.
- Optic-Camouflage Soldiers - Stealth Specialist Soldiers wearing optic-deflection armor suits to render themselves invisible to Batman's Detective Mode sensors.
- Suicide Bombers - Soldiers wearing explosive vests that detonate when they are rendered unconscious by Batman.
- Assault Rifles and other various firearms
- Grenades and other various explosives
- Swords and other various melee weapons
- Optic-Camouflage Suits
- Detective Mode Jamming Backpacks
- Detective Mode Tracking Devices
- Explosive Vests
- Unmanned Tank Drones
- Armored Jeeps
- Aerial Drones
- Venezuela - Founding base and training facility. (formerly)
- Gotham City - New and de-facto headquarters.
- Arkham Asylum - Scarecrow's personal lair.
- Checkpoints - Street military fortifications fortified all around Gotham.
- Watchtowers - Rooftop observation points placed all over Gotham.
- Small Dock, Bleake Island - A minuscule port that acts as a hiding point for a group of militia soldiers, and was where Mr. Freeze's wife, Nora Fries, was originally being kept before they found a tracking device on her.
- Ace Chemicals Processing Plant, Bleak Island - The staging ground for the Militia's invasion and occupation of Gotham. (destroyed)
- Scarecrow's Penthouse in Chinatown, Bleake Island. A laboratory on a building rooftop where Scarecrow's new Fear Toxin is tested.
- Underground Tunnels on Miagani Island - An underground installation where unmanned tank drones, APCs, and armored jeeps are built and/or repaired.
- Grand Avenue Station, Miagani Island - A subway station in which the Militia's access point for hard-wiring into the city transport network is embedded.
- Killinger Department Store in Drescher, Founder's Island - The Arkham Knight's personal headquarters.
- Two Unidentified Buildings in Ryker Heights, Founder's Island - Two separate buildings that each house militia radar satellites on their respective rooftops that can detect the Batmobile or Batwing if Batman uses either vehicle and enters Founder's Island.
- Unidentified Building in Otisburg, Founder's Island - An abandoned building rooftop that acts as a rendezvous point for a contingent of militia soldiers that are holding Nora Fries prisoner after being tranported there form the small port on Bleake Island.
- Large Under-Construction Building in Ryker Heights, Founder's Island - A large building still under-construction that house's the Militia's long-range missile launcher (Python Drone) that can take out the Batmobile or Batwing by surprise with help from the two radar towers if Batman uses either vehicle and enters Founder's Island.
- Port Adams, Founder's Island - A container yard that acts as a manufacturing point for unmanned tank drones.
- Under-Construction Subway System underneath Founder's Island - Underground facility that is accessible and can also be exited via the elevator in the middle of Port Adams on Founder's Island.
- During the main story of Arkham Knight, one of the APC lieutenants nearly got his head crushed by the Batmobile's tires. It's possible that this is one of the factors that lead to the game receiving an M-rating, due to Batman outright torturing the man to gather Intel on the Arkham Knight.