Mr. Casey is a high school shop teacher in Steven King's 1983 novel Christine.
Mr. Casey was a shop teacher at Libertyville High School, the school that Arnie Cunningham, Dennis Guilder and Buddy Repperton and his gang all attend. He is described as a short, unassuming, mostly quiet, man.
Early in the story, Arnie is harassed by Buddy and his friends in the desginated smoking area of the school near the shop classrooms. Buddy steps on Arnie's lunchbag and threatens him with a switchblade. Arnie's best friend, Dennis, fights off one of Buddy's gang, Don Vandenberg, but is himself attacked by another of Buddy's friends, Moochie Welch, who squeezes his crotch. Right before getting involved, Dennis had ordered an unnamed student to go and find Mr. Casey in the shop teacher's office.
When Mr. Casey arrives, Arnie, more by blind luck than fighting ability, has disarmed Buddy. Buddy quickly grabs up his switchblade and hides it in one of his back pockets. When Mr. Casey begins to question Arnie and Dennis about the altercation, Buddy immediately starts to mouth off and insult Arnie. Mr. Casey suddenly grabs Buddy and slams him against a nearby wall several times, showing a surprising amount of strength for such a smallish man. When he finds out about the switchblade, he demands that Buddy empty his pockets. Buddy protests, but Mr. Casey remains calm and Buddy gives in, slamming the switchblade on the tarmac. Buddy is later reported to have been expelled and Moochie and Don are suspended.
Dennis states that "Mr. Casey got respect" despite being smaller than most students. Dennis goes on to say that Casey was the type of teacher who wasn't "afraid of students deep down inside the way that so many teachers are ."
In the film, Mr. Casey's character has a brief appearance. The scene from the book is faithfully recreated on film. He is played by actor David Spielberg.