It is perhaps one of the easiest cases Patricia Cornwell has solved. The crime writer has spent this week in a Virginia court asking a judge to stop another, less well-selling author from posting defamatory messages about her on the internet, in what an expert witness described as “cyber-stalking.”

The saga has been more drawn out than one of Ms. Cornwell’s page-turners. In 2000 Leslie Sachs claimed that she had plagiarized his novel The Virginia Ghost Murders. A judge issued an injunction but Mr. Sachs continued filling his website with invective against Ms. Cornwell, describing her as a “Jew-hater,” a felon under federal investigation, and a “neo-Nazi.”

She is now seeking an enforcement of the earlier injunction and also suing for libel, claiming Mr. Sachs has damaged her reputation by potentially harming her ability to gain access to sources that could help her research.

Ms. Cornwell denied anti-Semitism and said her husband was Jewish. She said Mr. Sachs’s rants were a “huge distraction from the creative process,” had caused her to hire two full-time bodyguards and prohibited her from making personal appearances to promote her last two novels. In an interview after the opening hearing, Cornwell said there should be limits on the Internet. “There are so many people who can be damaged, it’s really quite frightening,” she said.

“Someone should not be able to run away from the consequences of their despicable behavior.”

Mr. Sachs left for Belgium in 2004 as a self-proclaimed “refugee” from Ms. Cornwell’s legal actions. He was not represented in court.