He was born on June 15, 1995. His birthday is the day after his parents, Gordon and Margaret Miller, were killed in a car accident. His mother was apparently kept on life support long enough for doctors to deliver Jackson via c-section.
Jackson was then adopted by attorney David Whittemore and his wife. His father says his son hasn't said "I love you" since learning he was adopted and that the circumstances of his parentage cause the teen to labor under self-imposed unrealistic expectations.
Jackson is to get a large insurance settlement connected to his bio-parents's death when he turns 18.
Scott McCall’s sudden improvement on the lacrosse field threatens Jackson’s supremacy, makes him suspicious and prompts his investigation of Scott, and eventually Derek Hale, who he believed was dealing steroids. Over several episodes, Jackson has witnessed many of Scott’s enhanced abilities including his speed and strength.
In Lunatic, he discovers a claw embedded in his SUV and connects it with the odd holes he found in one of Scott’s lacrosse gloves.
In Magic Bullet, Jackson was scratched on the back of the neck by Derek, a Beta Werewolf suffering from wolfsbane poisoning. The scratches did not heal well and Jackson’s behavior became bizarre and frightening.
He seemed to suffer a physical and mental breakdown during The Tell and in Heart Monitor. During that time he began to hallucinate. While he seemed physically recovered in Night School, a deep growl from The Alpha caused Jackson intense pain and which led to him collapsing.
Jackson’s had two close encounters with The Alpha. His first came during The Tell when he saw and was touched by the creature after an attack at the Video 2*C Store. He saw The Alpha again at the high school in Night School. While he doesn’t yet know for sure what he’s seen, he tells Allison Argent that he doesn’t believe it was human.
In Co-Captain, Chris Argent tampers with Jackson's car in order to force a breakdown as an excuse to approach the boy and question him. Derek wants to get Jackson out of the way so that he cannot expose Scott, but Scott intervenes.
In Formality, Scott forces Jackson to take Allison to their formal dance, since he's not allowed to go. While there, he drinks, and sees red lights in the woods. Thinking it's the Alpha he begs to be transformed. Instead, it is Chris Argent. He then tells them that Scott is the other Beta.
In the season finale, Jackson helps Lydia get aid for her injuries. Then he helps Scott, Stiles, Allison, and Derek defeat Peter Hale, the Alpha Werewolf. He then goes to the Hale House to ask Derek for the bite.
Derek bit Jackson but his body rejects the bite for unknown reasons. The rejection causes a black viscous liquid to ooze from his ears, and nose. (read more...)
Still thinking he would become a werewolf, he tried to film himself shifting on the full moon but got several hours of footage of himself sleeping and still very much human. (read more...)
He goes to Derek looking for answers but finds Chris and the Hunters instead. Chris suggests he stop trying to become a werewolf. That night on the lacrosse field his truck is stuck in the mud. In a moment of frustration he lifts the truck almost completely off the ground. read more...)
Derek feeds Jackson kanima venom to see if he is the creature. Jackson is paralyzed suggesting the venom did not come from him. The partially restored portions of the full moon video show him sit up in bed. His eyes begin to glow. After a fight and a kiss with Lydia, Jackson transforms into a Kanima and is drawn to meet with someone in a car on a lonely road. (read more...)
Jackson, in kanima form, fights Derek to a standstill, is shot several times by Chris Argent and seems to bow before Gerard. Then, at a gay dance club called Jungle, he apparently paralyzes several patrons and Danny. Derek shows up and slits his throat but he seems to heal and is next seen in human form bloody but unharmed. Stiles, Scott and Allison lock him in a Sheriff's van. He says he doesn't remember anything they claim he did as the kanima. He transforms into the kanima and escapes. He is next seen in human form at the Sheriff's office with his father. (read more...)
Jackson secures a restraining order against Stiles and Scott which requires them to maintain a distance of 50 feet and cease all harassment. At school, Jackson allows a snake to crawl down his throat. Allison tries to talk to him but he becomes violent. Naked in the locker room, he threatens her. She attempts to physically restrain him but fails. He then shakes himself and seems to not remember the exchange. Scott sees him, naked, on top of Allison and attacks. They fight, destroy property and end up in detention. Jackson partially transforms into the kanima and attacks Matt and Erica before scrawling a warning on the library chalkboard. (read more...)
Jackson is possessed by the Kanima Master and attends a secret rave party to reach his next victim. Stiles, Erica, and Isaac drug him with ketamine and interrogate him. The master, speaking through Jackson, says those he's killed so far were all murderers guilty of killing "me" meaning the master. Jackson transforms into full kanima, escapes and kills the party promoter, Kara Simmons. (read more...)
Jackson warns Lydia that she doesn't want him at her birthday party. At the party, Jackson hallucinates that two faceless people are looking for him because, they say, they are his parents. He saves Matt from drowning in the pool. (read more...)
When Matt captures people at the police station he is mostly in kanima form killing everyone Matt wants him to. Later when Gerard kills Matt, Jackson becomes his tool of vengence. (read more...)
At the lacrosse game, Jackson warns Danny if he begins to act weird on the field, he is to run away. Later when the game ends the lights go out, and when they come back on Jackson is lying on the field; not breathing. He apparently clawed himself in the chest. (read more...)
Jackson is dead. He is removed from the field in a body bag. A clear viscous liquid seeps from the bag. When Mrs. McCall opens the bag she finds him encased in a clear cocoon from the neck down. He begins twitching and eventually fully revives. Gerard uses the Kanima form to attack the werewolves and even Allison but once Gerard is incapacitated the Kanima is free of his influence. Lydia uses the house key Jackson gave her to remind him of his true identity. He transforms back to human form and Derek and Peter attack and kill him again. Somehow his wounds heal and he stands up transformed into a werewolf with blue eyes. He and Lydia reconcile. (read more...)
Lydia explains that the doctors looked like total idiots after he turned up alive (since he “died” in Battlefield). She says Derek taught him the "Werewolf 101" like how NOT to randomly kill people during the full moon. Lydia says his dad moved him to London. She makes a joke that an “American werewolf in London” will be a disaster, a reference to the 1981 film of the same name. (read more...)
Jackson is again mentioned when Stiles is trying to convince his dad that shapeshifters are real. Stiles succinctly sums up Jackson's situation, "Jackson was the Kanima first then Peter and Derek killed him and he came back to life as a werewolf and now he’s in London." (read more...)
Jackson is mentioned again when Derek and Chris are in jail discussing the situation in Echo House.
- “I've decided to drop some of the dead weight in my life, and you're about the deadest.” — Jackson to Lydia in Wolf's Bane.
- “For the record, I'm everybody's type.” — Jackson to Danny in Abomination.