According to ChatGPT:
"John Lennon was murdered by **Mark David Chapman** on December 8, 1980, outside Lennon's apartment building, The Dakota, in New York City.
Chapman’s stated reason for the murder has varied, but his main explanation was that he wanted to achieve fame. He had also become obsessed with J.D. Salinger's novel *The Catcher in the Rye* and viewed himself as a sort of protector of innocence, believing Lennon to be a "phony," a term frequently used in the novel. Chapman claimed that he was angered by what he perceived as Lennon’s hypocrisy, particularly Lennon’s wealth and lifestyle, which he thought contradicted the message of peace and love Lennon promoted in his music. He also cited religious reasons, being upset with Lennon’s 1966 comment that the Beatles were "more popular than Jesus."
Chapman’s mental health issues, combined with these motivations, led him to stalk Lennon for several days before committing the murder."