Joseph L. Gormley, 90, retired chief of chemistry and toxicology for the FBI and part-time perfumer, died of complications of cancer June 6 at the Chevy Chase House.

Mr. Gormley spent 33 years at the FBI laboratory, with many assignments in the field investigating major crimes, including some of the FBI's most famous cases. He was directly involved in the investigation of the Great Brinks Robbery in Boston in 1950, the Bobby Greenlease kidnapping in Kansas City in 1953 and the deaths of three young civil rights workers in Neshoba County, Miss., in 1964, which became known as the "Mississippi Burning" case.

He testified frequently as an expert witness in the fields of chemistry, toxicology and arson. He also supervised a program for more than 20 years to develop the use of polygraphs as scientifically valid devices for investigative purposes.

Mr. Gormley, the father of nine children, supplemented his government salary with a side business operated under his wife's name. He used his chemistry background to recreate well-known perfumes and fragrances, and sold the results to friends and acquaintances. The profits paid for his children's educations, a son said.

Born in Clinton, Mass., he graduated from Boston College with bachelor's and master's degrees in chemistry in 1940. He received law degrees from Georgetown University in 1948 and 1950 and a master's degree in forensic science in 1971 from George Washington University. He was a resident of Washington since 1940.

He went to work for the FBI in 1940, becoming a special agent two years later, and retired in 1973.

After his retirement, Mr. Gormley was appointed for a year as director of the Maine State Police Crime Laboratory. In 1974, he began a dozen years of work as a senior staff member in the research and training divisions of the International Association of Chiefs of Police.

He was an adjunct assistant professor at George Washington University from 1969 to 1973 and at the University of Maryland from 1974 to 1979.

Mr. Gormley was twice president of the Mid-Atlantic Association of Forensic Scientists. He was a charter member of the American Association of Police Polygraphists and a member of the American Society of Crime Laboratory Directors Accreditation Board. He was a member of the Society of Former Special Agents of the FBI, D.C. Chapter.

His wife of 60 years, Frances R. Gormley, died in 1996.

Survivors include nine children, Sheila A. LoJacono of Washington, Mark J. Gormley of Seattle, Maureen E. Mershon of South River, Md., Judith E. McDonald of Chevy Chase, Michael J. Gormley and Francis X. Gormley, both of Rockville, Kathleen G. Keany of Chevy Chase, Thomas M. Gormley of Potomac and Joseph I. Gormley of Olney; 36 grandchildren; and 48 great-grandchildren.