Nothing is known about Jeffries's life before or as the outbreak began. It is possible that he used to live in or near Atlanta before the outbreak.
Jeffries is first seen helping Dawn Lerner with a task. Later, he walks with Dawn to her office, and when Dawn stops to talk to Beth, Jeffries continues down the hall to Dawn's office, where he is attacked and devoured by a zombified Joan.
Jeffries is mentioned several times by Dawn Lerner when she is speaking with Beth.
While Beth is talking to Dawn, she tells her that Joan and Gorman are looking for her in her office and Jeffries accompanies her there. After walking towards Dawn's office, Jeffries is attacked by a zombified Joan. When Beth and Noah start to escape, Jeffries is heard screaming as he is attacked and fed upon. He is later put down by Dawn before he can reanimate.
This list shows the victims Jeffries has killed:
- Possibly numerous counts of zombies
- "Slabtown" (No Lines)