WORCESTER, Mass. — William G. Tapply, Clark’s writer-in-residence and professor of English, died July 28, 2009, at his home in Hancock, N.H., of leukemia. He was 69.

Decades of students knew Tapply through the classes he taught since arriving at Clark in 1995. But countless readers knew Tapply as the author of more than 40 books, especially the two dozen novels in his “Brady Coyne” mystery series. Tapply’s handbook, The Elements of Mystery Fiction: Writing a Modern Whodunit, is used in writing classes and workshops across the country. “I put Bill up with [mystery writer] Robert Parker,’’ Kate Mattes, who owned a popular mystery book store in Cambridge, told the Boston Globe.

Tapply also was widely respected for his writings on fly-fishing and the outdoors; his essays and articles were regularly published in Field and Stream and American Angler. A member of Mystery Writers of America and Authors Guild, Tapply and his wife, Vicki Stiefel, ran the Writers Studio at Chickadee Farm in Hancock.

Tapply received a B.A. from Amherst College in 1962, and the following year earned his M.A.T. from Harvard University. For nearly 25 years he taught social studies at Lexington High School before turning to writing full time.

In addition to Stiefel, Tapply is survived by a son, two daughters, two stepsons, his mother and a sister. A celebration of his life will be held Sept. 13 in Hancock. Details will be posted on his website.