Charles Renfrew Thomson, 61, a special agent with the Bureau of Alcohol, Tobacco and Firearms who helped apprehend the people who bombed the World Trade Center in 1993, died of a heart attack July 3 at his home in Alexandria.

From 1989 to 1993, Mr. Thomson was special agent in charge of the ATF's New York field division. On Feb. 26, 1993, he was leaving the World Trade Center garage on his way home when he heard an explosion that was intended to bring down the building. Within a few days of the bombing, two dozen of his agents, working with law enforcement personnel from numerous agencies, discovered evidence that led to the arrest and conviction of those responsible.

Later in 1993, he became associate director for law enforcement at ATF headquarters in Washington, with responsibility for all ATF field offices and five headquarters divisions. As associate director, he oversaw the bureau's response to the 1995 Oklahoma City bombing, an investigation for which he received the Presidential Rank Award.

Mr. Thomson was born in New York City and grew up in Amesbury, Mass. He received a bachelor's degree in history from Dartmouth College in 1965.

He was a captain in the Army from 1967 to 1970, serving as a helicopter pilot in Vietnam in 1967 and '68 and then working in surveillance on the border between East and West Germany. His duties included monitoring the movement of Soviet nuclear warheads along the Iron Curtain in Europe.

He began his career with the ATF in 1971 as an undercover field agent in the New England area. Later he became group supervisor in Philadelphia, where he headed the bureau's first arson task force. That experience led to a career-long involvement in ATF arson investigations and special-agent training.

In 1980, as assistant special agent in charge of the Washington field division, he headed a multi-agency task force that resulted in the arrest of those involved in the bombing of 10 abortion clinics. For his work on that case, he received a leadership award from the secretary of the treasury.

He then served as an ATF liaison to William W. Nickerson, deputy assistant secretary of the treasury for enforcement, a post in which he worked on money laundering, tax fraud and financial security investigations.

During his tenure as special agent in charge of the New York field division, he directed investigations into the activities of career criminals, narcotics traffickers, arsonists and those dealing illegally in firearms, as well as the World Trade Center bombers.

In 1995, he was appointed special agent in charge of the District and Virginia field division. In Richmond, he was involved with Project Exile, an initiative to bring all firearms crimes under federal jurisdiction. After a dramatic reduction in Richmond's crime rate, Project Exile was adopted nationwide.

Mr. Thomson retired in 1999, although he continued to work from his home as a consultant on crisis management, anti-terrorism and other law enforcement issues. He moved to Alexandria in 2003.

Retirement allowed him to indulge two of his years-long interests: growing bonsai plants, flowers and trees, and re-creating Native American culture, particularly traditional arts.

"He loved working with his hands," his wife said. "That was his way of relaxing."

His home was filled with tomahawks, toys, spirit sticks and other objects he carved in the Native American style from wood and stone he found in the New England and Washington area countryside. "He thought it was a thing of beauty to re-create their craft," his wife said.

Mr. Thomson's marriage to Diane Gould Thomson ended in divorce. A son from that marriage, Charles "Chuck" Thomson, died in 1986.

Survivors include his wife of eight years, Louise Lindblom Thomson of Alexandria; a son from his first marriage, Eric Thomson of Durham, N.C.; two stepchildren from his second marriage, Stephanie Eby of Alexandria and Hunter Lindblom of Birmingham; his mother, Lavinia Thomson of Amesbury; and a sister and brother.

Charles Thomson, 61, of Alexandria worked in the ATF bureau for nearly 30 years.