The feature works similar to other explosives, but it can only be used outdoors or when the enemy is in clear view of a window or open door. When equipped, a circle will appear on the ground that can be maneuvered to encircle one or more enemy NPCs. Anyone within the circle will be taken out by a headshot from a sniper.
The feature becomes available after first speaking with Robert Marshall in the mission Creature of Habit. Lincoln can carry a maximum of three markers, and despite them being listed under equipment, the IRA Bomber perk does not increase the amount. Additional support markers can be purchased from the Arms Dealer.
- One can be found in the garage at Marshall's Office.
- The service cannot be used to kill civilian NPCs.
- Despite being listed under equipment, Lincoln's carry capacity is not affected by the IRA Bomber perk.
- Unlike other items under the equipment menu, they are not picked up automatically. The player must use the interact button to add them to their inventory.