CELEBRITY STALKING NIGHTMARES

John Lennon

■ The Beatles legend was murdered by maniac Mark David Chapman outside the Dakota Hotel on the Upper West Side. Chapman, a big Beatles fan, waited outside the hotel for Lennon, who signed an album for him. Chapman shot Lennon, 40, before opening a copy of J.D. Salinger’s “The Catcher in the Rye” as he waited for police.

Rebecca Schaeffer

■ The actress-model was tragically shot and killed by stalker Robert Bardo after answering the front door of her Los Angeles apartment in 1989 when she was 21 years old. Bardo, an obsessed fan, paid a private investigator to track down her address through vehicle records. Bardo remains in prison, serving a life sentence without the possibility of parole for the murder.

Theresa Saldana

■ The “Raging Bull” actress was approached by a crazed stalker outside her West Hollywood apartment in 1982. The stranger asked her if she was the famous actress. When she said yes, violent superfan Arthur Jackson stabbed her multiple times with a hunting knife. Saldana survived when a delivery driver fought off the attacker and pinned him down until cops arrived.

Christina Grimmie

■ The “Voice” singer and YouTube star was killed by an obsessed fan while signing autographs at a 2016 postconcert event in Orlando, Fla. Gunman Kevin Loibl was infatuated with her and believed they would get married.

Madonna

■ Madonna’s security guards shot stalker Robert Dewey Hoskins after he hopped the fence at her Hollywood Hills estate in 1995. Hoskins said he wanted to marry Madonna or slash her throat from ear to ear. The queen of pop was in Miami at the time. Hoskins served a 10year prison sentence for stalking and threatening Madonna following a 1996 conviction.