In the FBI office there, Darcy said, "three of us were assigned to it," including Mr. Mallon. It was, said Darcy, "a significant case."
Born in Philadelphia, Mr. Mallon earned a bachelor's in accounting at La Salle University in 1969 and worked for a year as a certified public accountant in the Philadelphia office of the former accounting firm Haskins & Sells.
But his wife, Elizabeth, recalled that "he came home one night, around Christmas, and said, 'I don't like putting those little numbers into those little boxes.' "
And an FBI career was born.
Organized crime at the time was in the news, she said, "and he was hired because of organized crime."
Mr. Mallon's career as an FBI special agent, which began in 1972, took him to agency offices in Buffalo, Newark, N.J., and Detroit.
Then, as a supervisor in the Atlantic City office from 1998 to his retirement in 2004, he oversaw investigations into fraud, white-collar crime, and public corruption.
In 2005, Darcy and Mr. Mallon opened J&J Investigations in Ocean City, from which Mr. Mallon retired in 2010.
Besides his wife of 45 years, he is survived by son James P. III, daughter Jennifer Quade, and three grandchildren.
Visitations were set from 6 to 8 p.m. Thursday, Aug. 21, and from 9 to 9:45 a.m. Friday, Aug. 22, at the Wimberg Funeral Home, 211 E. Great Creek Rd., Galloway, N.J., before a 10 a.m. Funeral Mass at the Church of the Assumption, 146 S. Pitney Rd., Galloway, with burial in Holy Cross Cemetery, Mays Landing, N.J.
Donations may be sent to the Brendan Borek High Tides Memorial Fund, Inc., Box 41, Avalon N.J. 08202, or to http://brendansfund.org.
Condolences may be offered to the family at www.wimbergfuneralhome.com.