The former Ellicott City resident was 68.
Born in Baltimore and raised in Catonsville, Mr. Miller was a 1961 graduate of Loyola High School and earned a bachelor's degree in political science in 1965 from what is now Loyola University Maryland.
After working as a social worker for the city Department of Social Services and studying psychology, Mr. Miller left Baltimore in the early 1970s and went to California, where he began reporting for the San Jose Mercury and later the Sacramento Bee.
He became the primary researcher for authors George Klineman, Sherman Butler and David Conn, whose book, "The Cult That Died: The Tragedy of Jim Jones and the People's Temple," published in 1990, told the story of the 1978 Jonestown Massacre in Guyana.
He began working in 1984 for United Press International in San Francisco, and later was transferred to Washington, where he was assigned to the international desk.
During his three-decade reporting and editing career, he lived and worked in 26 countries, and covered the 1991 Gulf War.
After leaving UPI in 1992, he did stints with the Associated Press in Nicosia, Cyprus, and later with Reuters in Hong Kong, and also reported for the English language edition of Haaretz, Israel's oldest daily newspaper.
"He once said that he had spent 30 years in news, the best 10 with UPI," said a brother, Scott Miller of Ellicott City.
"He was a very colorful character," said Frank T. Csongos, former UPI Washington Bureau chief who now teaches international journalism at George Mason University.
"He was hardworking. Brilliant. Serious. And sometimes difficult," said Mr. Csongos. "But Tony was a really decent editor and writer."
David Rosso, a former UPI colleague who worked alongside Mr. Miller in Washington, said, "He was vocal. He was energetic. He was ALL CAPS. He was excitable. He was personable. He was agreeable. He was sometimes disagreeable, and he valued his Unipresser days."
After retiring from journalism in the early 2000s, he lived in Cuernavaca, where he taught English literature, history and geography.
Diagnosed with prostate cancer, he returned to Ellicott City in 2008, and a year later returned to his home in Cuernavaca.
He was an avid reader and collector of first editions of the work of John Steinbeck.
He was cremated in Mexico, and graveside services in Baltimore will be private, family members said.
Mr. Miller is survived by two other brothers, Mark Miller of Clear Spring, Washington County, and Kelly Miller of Arbutus; three sisters, Krista Nordhoff of Ellicott City, Mary Dorshiemer of Dover, Mass., and Laurie Saxon of Oxford, Ga.; and 19 nieces and nephews. Two marriages ended in divorce.