An interesting article from Investigation Discovery's Crime Countdowns of the Top Celebrity Stalkers. Unfortunately, this article didn't include Heidemarie Schnitzer so we have taken the liberty of adding her name and photo to the list :
No. 1 - Mark David Chapman, John Lennon Stalker/Assassin
In the fall of 1980, Mark David Chapman traveled to New York City with the intention of killing former Beatles singer and political activist, John Lennon. After spending the afternoon outside Lennon's apartment — an afternoon that included receiving an autograph from Lennon and shaking his young son's hand — Chapman shot the music legend in the back multiple times when he attempted to enter his apartment.
As Lennon lay dying from his wounds on the sidewalk, Chapman remained on the scene and casually read passages from the book, A Catcher in the Rye. He was sentenced to 20 years in prison.
No. 2 - Robert John Bardo, Rebecca Schaeffer Murderer
In 1989, Rebecca Schaeffer was a Hollywood darling, former star of the television series My Sister Sam and several movies. But just as her career was taking off, her life was cut short by Robert John Bardo, a man who had been stalking Schaeffer for years. In July 1989, Bardo showed up at Schaeffer's apartment and fatally shot her as she stood in her doorway.
Bardo's crime sent chills through Hollywood, especially because of the ease with which he found Schaeffer through her driving records. The incident led to new anti-stalking laws, including the 1994 Driver's Privacy Protection Act, which prevents the Department of Motor Vehicles from releasing private addresses.
No. 3 - Anthony Gary Silvestri, Kathryn Dettman Murderer
In January 1998, Anthony Gary Silvestri broke into the home of television reporter Kathryn Dettman, a woman he had been stalking for many months. As Dettman stepped out of her shower and into her bedroom, Silvestri stood waiting for her with a knife. What ensued was a brutally violent attack: Silvestri stabbed Dettman more than a dozen times, leaving her dead on the apartment floor. He is currently serving a 40-year prison term.
No. 4 - John Hinckley Jr., Jodie Foster Stalker/Would-Be Ronald Reagan Assassin
In 1980, actress Jodie Foster took a break from Hollywood to become a student at Yale University. It's also the year she became the victim of a stalker. John Hinckley Jr., was obsessed with Foster and enrolled at Yale for the sole purpose of being close to her. He soon began to leave letters and poems in her mailbox, including one in which he outlined plans to assassinate President Ronald Reagan in an effort to win her affections. On that same day, Hinckley traveled to a hotel in Washington, D.C., and made good on his promise, shooting President Reagan and other members of his party. Reagan survived. Hinckley was found not guilty by reason of insanity.
No. 5 - Margaret Mary Ray, David Letterman Stalker
For many years, schizophrenia patient Margaret Mary Ray stalked David Letterman, of The Late Show With David Letterman, and entertained fantasies about being his lover. Though he joked about her on his show, the threats Ray made against Letterman were no laughing matter. She broke into his home on several occasions and stole his Porsche at least once. Ray died by her own hand in 1998.
No. 6 - Jack Jordan, Uma Thurman Stalker
At the trial of Jack Jordan, Uma Thurman's long-time stalker, the actress testified that she was "totally freaked out" and scared for herself and her children when confronted with Jordan's creepy advances. In an attempt to spark a love interest, Jordan had sent Thurman cards with sexually suggestive messages and threatening drawings, including one of an open grave, a headstone and a man standing on the edge of a razor blade. He was found guilty and sentenced to three years probation.
No. 7 - Cristin Keleher, George Harrison Stalker
Cristin Keleher gained infamy in 1999 when she broke into the home of former Beatles guitarist George Harrison and helped herself to a frozen pizza. She wasn't just overcome by munchies; Harrison had been the object of Keleher's stalker fantasies for years. She served four months for the crime, but was back in the news in 2006 when she was fatally shot in California, the victim of a murder-suicide.
No. 8 - Dawnette Knight, Catherine Zeta-Jones/Michael Douglas Stalker
When Dawnette Knight developed an obsession with actor Michael Douglas, his wife Catherine Zeta-Jones became her natural enemy. In 2003 and 2004, Knight sent threatening letters to the Oscar-winning couple, which included claims that Knight would cut up Zeta-Jones and feed her to dogs. Following a much-publicized trial in which both Zeta-Jones and Douglas gave harrowing testimony, Knight pleaded guilty and was sentenced to three years in prison.
No. 9 - Rev. David Ajemian, Conan O'Brien Stalker
After the molestation scandals of the 1990s, the Catholic Church had endured about as much negative publicity as it could handle. Enter Rev. David Ajemian, the stalker priest who sent threatening letters and DVDs to Conan O'Brien of NBC's Late Night With Conan O'Brien. Ajemian pleaded guilty in 2007 to disorderly conduct and agreed to stay away from the late-night talk-show host. He was placed on leave by the Archdiocese of Boston after the scandal broke and was later stripped of his priestly duties entirely.
No. 10 - Heidemarie Schnitzer, Stalker /Would-Be Assassin of David Caruso
Heidemarie Schnitzer, Austrian national charged with stalking and threatening to murder David Caruso, his grown daughter Greta and his former companion, Liza Marquez. After Caruso failed to furnish her with an autograph and rejected her sexual advances in a Miami restaurant, Schnitzer went off the deep end. Her love obsession for the actor turned to a deadly hate obsession. Dr. Karin Treichl, an Austrian psychiatrist, diagnosed Schnitzer with "severe personality disorder capable of turning violent at any time."
Schnitzer failed to appear for two trial dates and fled to Mexico's Baja peninsula in April 2008. Armed with a laptop, Schnitzer launched an Internet hate campaign against David Caruso, his family and his associates. Using hundreds of pseudonyms and writing four hate-Caruso blogs, Schnitzer libeled and denigrated the actor for the duration of her flight from justice. On one website, Schnitzer posted a pornographic comment about Caruso's two-year old son. Sources close to this story always feared that Schnitzer would attempt to breach the US/Mexico border and travel to Los Angeles to hunt down Caruso and his family.
On February 19, 2009, Tijuana police captured and arrested Heidemarie Schnitzer pursuant to an international warrant. Two months later, Schnitzer was tried and convicted of stalking and sending death threats to David Caruso. During her trial, evidence of Schnitzer's 1994 conviction for threatening an ex-boyfriend was introduced by the prosecution. Judge Guenther Boehler sentenced Schnitzer to seven months in prison followed by incarceration in a mental facility for an undisclosed period of time.