Prior to the outbreak, Boone was fighting in Afghanistan along with the rest of his squad which included a lot of members that would eventually become the Reapers. Upon returning from war, he struggled to find jobs or deal with trauma, but the relationship between him and his comrades remained strong. He then decided to become a mercenary.
During the beginning of the outbreak, as Operation Cobalt was put into action in an attempt to try and contain the undead threat, Pope and a group of his people managed to escape the bombings by running until they reached an abandoned church, where inside Pope was amazed to see none of them had been killed or injured, leading him to view him and his comrades as "the chosen ones". It is unknown if Boone was present during this revelation. Regardless, he eventually joined the Reapers, and either found or crafted his own mask with a monochrome black-white pattern and a pair of fangs on it, and would use this mask as a scare tactic against those who were "marked" by Pope.
Boone and at least a dozen Reapers appear on a dark road adorned on both sides with bodies hanging from posts. Suddenly, the Reapers open fire on Maggie and her group, killing Roy and severely injuring Cole. As the Alexandrians flee into the woods, the Reapers chase after them.
Chaos breaks out in the woods as Boone and the Reapers hunt down members of Maggie’s group, killing Cole and injuring several others, including Duncan, Negan, Daryl, and Gabriel.
Boone is present at Daryl's initiation, waiting outside with all the other Reapers for the inductee to pass the test. As Pope declares Daryl "forged by fire", Boone and the rest of the Reapers welcome Daryl with a latin mantra. He is later seen at a bonfire where the Reapers are eating dinner. He later watches in silence as Pope burns Bossie alive for presumed betrayal, claiming he allowed Michael to be killed in order to save himself.
After Leah kills Pope and radios everyone that Daryl murdered their leader and is with the enemy, Boone arrives with Brandon Carver seconds after Daryl manages to escape. Leah instructs them to close the gates and kill everything inside the walls.
This list shows the victims Boone has killed:
- Teresa (Possibly)
- Elijah's Sister (Possibly)
- Roy (Possibly)
- Duncan (Possibly)
- Numerous counts of enemy combatants (Pre-Apocalypse)
- Possibly some unnamed contracted victims (Pre-Apocalypse)
- Possibly some unnamed Wardens
- Numerous counts of zombies and unnamed people