David Kreider Shroyer Jr., 65, a retired Marine Corps colonel who specialized in mobilization planning, died of pancreatic cancer July 22 at his home in Oakton.

He retired from Marine Corps headquarters in 1985 as executive assistant to the deputy chief of staff for plans, policies and operations. Since then, he had been a senior analyst and program manager for Jaycor Inc., a defense contractor, consulting on contingency planning, operations and management.

Col. Shroyer was a native of Annville, Pa., and a graduate of the U.S. Naval Academy at Annapolis. He received a second bachelor's degree, in electrical engineering, from the Naval Postgraduate School and a master's degree in administration from George Washington University.

During 27 years in the military, Col. Shroyer commanded a communications detachment and was a communications officer in Vietnam, where he also was executive officer of the 5th Marine Regiment.

He commanded a supply battalion in Okinawa and was an adviser to the director of mobilization plans in Washington.

His honors included the Legion of Merit, the Defense Superior Service Medal, the Bronze Star, the Army Commendation Medal and a certificate of appreciation for civilian service from the Defense Department.

Col. Shroyer was an elder and choir member at Falls Church Presbyterian Church and a member of the Retired Officers Association.

Survivors include his wife, Mary Elizabeth Swope Shroyer of Oakton; three daughters, Stephanie Jean Shroyer of Los Angeles, Rebecca Lynne Shroyer of Larchmont, N.Y., and Mary Beth Shroyer Elkjer of Ashburn; three sisters; and three grandchildren.