- "Our friend who was driving... did not survive. (...) It's not my fault, Brandon. (...) You were the one who said that it was not his party."
- —Derek to Madison and Brandon.[src]
San Diego, California
Few is known about Derek's life except that he was from San Diego and attended the UCSD together with James, Brandon and Troy. During the school vacation before the apocalypse, they had traveled down to the Sea of Cortez in Baja California to party.
Derek and his group are looting from a roadside taco stand in Baja California; the owners, Mr. and Mrs. Magaña, recently having been killed and dumped behind the counter. When zombies sneak inside, Derek and his group emerge from the kitchen to see Chris taking down the zombies.
That night, Derek and his group find Chris and Travis camping out on the side of the road and declare that they will be camping there as well. Derek, Brandon, and James open up to Travis and Chris, winning the trust of Chris. They offer to give Travis and Chris a ride since they don't have any gas to spare for their car. Derek and the others befriend Chris and they arrive at an abandoned farm. They find chickens inside the barn and start having fun chasing them. When the farmer enters the barn with a shotgun, Derek draws his firearm and refuses to stand down as Travis attempts to diffuse the situation. He witnesses Chris shoot and kill the farmer after James is shot.
Chris tackles Travis, pinning him down. Brandon and Derek rush in. Brandon shoots James dead, despite the latter's pleas for mercy. Later, Brandon and Derek load the truck. Travis, who is staying behind, desperately implores Chris to stay with him. Chris says he’s better off without Travis, and says that he has adapted to the new world, whereas Travis hasn't. He leaves the farm with Brandon and Derek.
Several days later, Derek appears at the gates of the Rosarito Beach Hotel with Brandon and a few other refugees, but without Chris.
Derek and the other refugees were admitted to the hotel and brought to the parking garage to be screened by Andrés and the other survivors. As Madison checks-in on the refugees, she is notified of Derek and Brandon's rowdy attitudes. As she introduces herself to the boys, they explain where they came from and how Brandon injured his arm. After realizing the boys are the ones who abandoned Travis at the farm, she quickly devises a plan to take them outside of the hotel and isolate them at a coffee shop to avoid Travis finding out about them. However, Travis witnesses the angry crowd of people following the boys and catches up to them. At the coffee shop, he asks about his son's whereabouts but realizes the boys are lying. After Madison, Andrés, and Oscar leave the shop, Travis locks the door and proceeds to beat the boys to death, despite the hotel survivors' pleas to stop.
After the boys' deaths, Madison proceeds to put down Derek before he could reanimate while killing a newly-reanimated Brandon.
This list shows the victims Derek has killed:
- Sr. and Sra. Magaña (Alongside Brandon and James)
- James McCallister (Caused)
- Numerous counts of zombies and possibly unnamed people
- Travis Manawa (Alive)
After admitting to Travis that he killed Chris due to his injuries sustained in the accident, Travis is sent into a blind rage, and begins savagely beating both Brandon and Derek. Brandon and Derek attempt to fight back, with Derek breaking a chair over Travis, but were overpowered. Travis defeats Derek by brutally strangling him then throwing him through a glass door, dying afterwards.
- Madison Clark (Before Reanimation)
Madison later stabs Derek in the head to prevent reanimation.
- The casting call for this character used the name Damien.
- He was described as "a nervous, lanky, southern California bro who is usually the butt of the joke. He likes to have a good time and fit in but, is cautious".