Dexter

"I'll make this really simple for you, farm boy. We were here

first--and you wore out your welcome real quick.

Get the fuck out of my house." — Dexter to Rick Grimes.

Dexter was a towering, physically intimidating African-American inmate who survived the outbreak trapped in The Prison cafeteria.

After- Apocalypse
Dexter was convicted of murdering his wife and her lover, but promises the survivors their murders "were the last".

Dexter ironically trusts the other survivors far less than they trust him. He had a covert homosexual relationship with Andrew, but was in the relationship purely for sex. After the murders of Susie and Rachel Greene, Lori lead the group to wrongly lock him up on account of being the only prisoner convicted for murder. After Thomas Richards is revealed to be responsible for the murders and not receiving any apology, he loses his patience and orders fellow inmate Andrew to scavenge the prison's riot gear.

Killed By
Rick Grimes

Amidst the confusion with Thomas, Dexter gathers Andrew and a defecting Patricia with their new riot gear to force out the survivors. He is soon after killed discreetly in a skirmish against zombies from Block A by Rick, who covers it up as a friendly fire mistake.

Killed Victims
This list shows the victims Dexter has killed:

Numerous counts of zombies and two unnamed people.

Andrew
Sometime during their imprisonment, he and Andrew had developed a homosexual relationship with one another. Dexter also knew how take advantage of Andrew's love for him, as seen by him manipulating him to let him out and get him riot gear.

Rick Grimes
Dexter saw Rick as a threat even more than he did to the other Atlanta survivors, due to the fact that he was the leader of their group. Dexter hated all of the Atlanta survivors, but none more than Rick. Later, when Rick spoke to Abraham about the prison and Dexter's death, he admitted that he regretted killing him, as he later felt he could have convinced Dexter not to kick them out.

Patricia
Patricia helped Dexter get the weapons to try to kick everyone out. When Dexter was shot and killed by Rick, Patricia was crying over his body.

Lori Grimes
Dexter didn't really talk to Lori until she blamed him for the murders of Susie and Rachel Greene and locked him in his cell. Dexter hated Lori, and the rest of her group apart from Patricia

Allen
Although Dexter and Allen were never seen talking, Dexter said Allen was weird and thought it was him that murdered Susie Greene and Rachel Greene.

Trivia
Dexter and Andrew are one of two homosexual couples. The other couple being the Alexandria Safe-Zone recruiters, Aaron and Eric.

It is worthy to note that Dexter was possibly not a true homosexual, but endured it for his needs during prison and when the world collapsed.