Inside the Mind of A Stalker

April 30, 3008—, 2008 -- As actress Uma Thurman prepares to take the stand Thursday in the trial of a man accused of stalking her for two years, forensic psychiatrist Dr. Michael Welner joined "Good Morning America" today to explain what makes a fan turn into a fanatic.

Thurman's alleged stalker is a 37-year-old University of Chicago graduate student turned pool cleaner. Prosecutors say that Jack Jordan sent a series of rambling letters and e-mails to Thurman and her family, including one that said "my hands should be on your body at all times."

Later, when Thurman was filming "My Super Ex-Girlfriend" in New York, witnesses say Jordan showed up at the set and tried to force his way into her trailer.

He even allegedly handed another note to Thurman's assistant, suggesting he and the star "get married." "After all," he wrote, "I feel like you've been stalking me."

Prosecutors also allege that Jordan came to Thurman's home in New York City, rang the doorbell, and sat on her steps.

Psychiatrist Welner said that Jordan, like most stalkers, doesn't have the background or credentials one might expect. Sheryl Crow's stalker, for instance, was a champion diver, he said.

"They have high opinions of themselves, because they feel they're worthy, yet they sit with an awareness of how difficult it is for them to connect with people on a one-to-one," Welner said.

Stalkers may fixate on a celebrity who seems larger than life to cure their own shame. "They say, 'If I'm special to this person and wrap myself around them, I can find someone I can connect to.' Unfortunately, their shame and their unrealistic ideas are quite delusional and difficult to turn off because it's so important for them," he said.

Welner explained that stalkers truly believe they have a relationship with the person that they idolize. Targets need to recognize that they are dealing with irrational people, he said, and that anything they do can feed into that and be misinterpreted.

"Rejection for someone who is so overly wrapped up in someone they idealize is a tipping point for some to become dangerous to the victims," Welner said.

If you're among the approximately 1.4 million people who've been in a stalking situation, Welner says the most important thing to do is to keep contact to a minimum.

"Unfortunately, it is more important to be distant and set limits. At a very early stage, make it clear to the person, in writing and briefly. You're causing me a lot of distress. This is stalking," Welner advised.

He also said it is important to use the term stalking to try and break their bubble of delusion.

"Lastly, point out to them the consequences of this is that you're going to the police."