- "He's not a monkey, he's an ape!"
- ―Robert Franklin
After being ordered to exterminate all chimpanzees exposed to a potentially dangerous drug, Robert discovered a new-born baby chimpanzee who he could not bring himself to euthanize. Unable to rescue the chimpanzee himself, due to his brother-in-law working in security, Robert asked Will to raise the chimpanzee, who was later named Caesar.
Eight years later, chimpanzee testing resumed at Gen-Sys and Robert returned to his former role. While the refined ALZ-113 drug was tested on a bonobo named Koba, the ape had a strong shake in his restraints and Robert was kicked in the face by Koba's wandering hand and exposed him to the 113 by pulling the formula's feed tube out, and even though he quickly put his mask back on properly he was infected with the virus. Realizing his mistake, Robert tried to get to Will to tell him that he had been infected, and met Will's neighbor, Hunsiker who wanted to know who Robert was and why he was in the neighborhood. A startled Robert accidentally sneezed coughed up blood on Hunsiker, passing the virus on to him, after which Hunsiker aggressively ordered him to leave. This act would cause the Simian Flu epidemic that would result in the fall of humanity. Soon after, Robert's body was discovered in his apartment by his neighbor, Dottie, his body still bleeding black after he had died. Linda Andersen phoned Jacobs to tell him about Franklin but was too late and ignored her due to Caesar's revolution inside the Gen-Sys building. The same fate would happen to Hunsiker and apparently, billions of humans worldwide. In the coming years after his death, Robert would be labelled as "Patient Zero", a lab technician who was the first to be exposed to the ALZ-113, now dubbed the "Simian Flu".
Robert was distinguished as being one of the only characters to care for the apes' well-being, at one point standing up to his unethical boss and proudly correcting Will's presumption of Caesar being a "monkey". He was also kind and was willing to take the infant Caesar if his brother-in-law hadn't worked in security. He was also known to have been clumsy as seen when he knocked his mask off his face, hence exposing him to the lethal ALZ-113 virus.
- Franklin's name is taken from Franklin J. Schaffner, director of the first Planet of the Apes movie.
- An earlier version of the script differed in the details of Franklin's fate. Instead of Franklin, it was a chimpanzee handler named Evans (perhaps in reference to Maurice Evans) who was infected with the ALZ-113 virus in the operating theatre and died as a result. Caesar and Rocket escaped from their facility and broke into the lab in search of Caesar's mother. In return for a bracelet, Rocket freed the sinister Koba, who then killed Franklin before returning to his cage, effectively framing Caesar for the murder. Later, Koba deliberately infected Steven Jacobs with the fatal virus, who in turn infected Hunsiker.
- Despite his kind nature, Franklin's actions with Hunsinker ended up being a cause of humanity's fall, as it would later turn out that Hunsinker was an airplane pilot and he would spread the disease across the entire world.
- The top quote references that apes in the Planet of the Apes franchise regard the name "monkey" as a serious derogatory offence.