Monday, October 18, 1999 Published at 15:35 GMT 16:35 UK
Stalking the stars
Brad Pitt: A fan broke into his home, dressed and slept in his clothes
Stardom has always guaranteed wealth, media attention and, it would seem, stalkers.
This weekend's incident involving Madonna - she had to be escorted off a plane at London's Heathrow Airport after receiving a threatening phone call - is the second time the superstar is known to have been harrassed by an obsessed fan.
In 1995, Robert Hoskins was prosecuted after scaling the security wall surrounding her Hollywood Hills home.
The tactics employed by celebrity stalkers can vary, from sending letters to full-scale break-in of their homes.
But, according to one UK psychologist, in nearly all cases, their extreme behaviour is a perversion of an otherwise natural and healthy interest in well-known figures.
"Fans who become stalkers are trying to satisfy a drive to become totally immersed in whoever they are into, regardless of the consequences and the risk of dangerous isolation," says Dr Sandy Wolfson, Principal Lecturer in Psychology at the University of Northumbria.
Dr Wolfson says that normal fan worship can have a number of positive results, including reducing tension and aiding social-interaction.
In January this year, a woman was arrested after she was found in actor Brad Pitt's Santa Monica home. She wanted to be close to him and dressed up and slept in his clothes.
The woman's actions pushed her into a minor transgression of the law. But, according to forensic psychologist Ian Steven, the type of obsession that compels a stalker can escalate.
"It is very difficult to treat because the reason for it is often rooted so far in the past. It can be treated and managed but often the root of the problem remains and can reappear as is shown when a stalker re-offends on release from prison," Steven said in a recent interview.
Last year, a man was jailed for 25 years after he was found outside Steven Spielberg's Los Angeles home with a "rape kit" consisting of tape, handcuffs, nipple clamps, and a knife.
The film director told the court how the stalker had carried out extensive research about him and his family. Despite the conviction, Spielberg believed the man's obsession would remain.
She adds that the line between threats and causing real harm is just as easily crossed.
"When an obsessed fan becomes violent, it is because something has ultimately led them to completely lose their grip and control of what is happening around them," she explains.
In Los Angeles, an estimated 15% of stalking cases turn violent - but sometimes with fatal consequences.
Famous cases include former Beatle John Lennon who was shot dead by Mark Chapman in New York in 1980. In 1989, rising actress Rebecca Schaeffer was also gunned down by obsessed fan Robert Bard. Tennis star Monica Seles was stabbed by a crazed Steffi Graf fan in 1993 in Munich.
On rare occasions, the celebrity has actually had a relationship with a stalker. NYPD Blue actress Andrea Thompson was stalked by a designer on the series with whom she had broken off a relationship.
What's more, stalking can happen to all sorts of people, both male and female, in all walks of life.
Figures up to April this year showed that in the UK more than 2,500 stalking cases were brought before the courts, 1,250 people were found guilty and 165 jailed over a period of six months.
Research carried out in the US last year estimated that over one million women and 370,000 men were stalked each year.
In the UK, anti-stalking legislation - the Protection from Harassment Act - was introduced in June 1997. In the US, different degrees of anti-stalking legislation have been introduced from state to state over the last decade.
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