Last Friday, Duquesne professor Patrick Juola got an email asking for help with a mystery straight out of a whodunit novel.

Could he help a reporter uncover the true author of a detective novel written under pseudonym?

And thus, the Pittsburgh connection to the unraveling of the true authorship of "The Cuckoo's Calling" -- that the mystery novel allegedly written by a first-time author and former soldier under the name Robert Galbraith was actually penned by Harry Potter author J.K. Rowling.

The discovery -- published over the weekend by the Sunday Times newspaper in London -- propelled the novel from No. 5,076 to No. 1 on Amazon.com.

For years, Mr. Juola has been developing technology that identifies patterns in written documents to infer authorship of documents. He is working on a project to authenticate early writings of Abraham Lincoln in a weekly newspaper in Illinois.

He also founded a consulting company, Juola & Associates, that analyzes documents for court cases. His work also has been recognized by the Plagiarism Action Network as one of the most accurate methods of authenticating authorship.

Mr. Juola asked Sunday Times reporter Cal Flyn to provide an electronic copy of "The Cuckoo's Calling" and "The Casual Vacancy," Ms. Rowling's other adult novel, as well as samples from similar works by other authors.

He ran four separate analyses of the works through his computer program, looking for the 100 most common words used in the texts, frequently appearing four-letter clusters of words, collections of words adjacent to each other and distribution of word lengths.

"Rowling kept coming up at or near the top of the list of candidates," he said. "This means that it was either Rowling herself or someone else who writes an awful lot like Rowling." The analysis itself only took about half an hour, he said.

Shortly after receiving Mr. Juola's analysis and that of a British linguistics expert, the Sunday Times got confirmation from Ms. Rowling that she had indeed written the novel.

"I hoped to keep this secret a little longer, because being Robert Galbraith has been such a liberating experience!" Ms. Rowling told the newspaper in a statement. "It has been wonderful to publish without hype or expectation and pure pleasure to get feedback from publishers and readers under a different name."

The novel received rave reviews, with Publishers Weekly calling it "a stellar debut." The author was described as a retired member of the Special Investigative Force of the Royal Military Police, with plot of the novel having grown "directly out of his own experiences and those of his military friends who returned to the civilian world."

Ms. Rowling also indicated that a sequel to the novel would be forthcoming. Publisher Little, Brown & Co. plans to release a revised edition with Ms. Rowling's name attached.

Mr. Juola, a fan of the Harry Potter books, had been meaning to read "The Casual Vacancy" in the near future. Now, "The Cuckoo's Calling" has gained priority.

"It's sitting on my shelf," he said.

First Published: July 16, 2013, 8:45 a.m.