Thomas Constantine, left, head of the Drug Enforcement Administration, with FBI Director Louis J. Freeh at a House Appropriations subcommittee hearing in 1996. (Ray Lustig/The Washington Post)

Thomas A. Constantine, a onetime state trooper who, as chief of the Drug Enforcement Administration in the 1990s, helped bring down a Colombian cocaine cartel and whose straight talk about Mexican drug trafficking created a diplomatic stir, died May 3 at a hospice in Pinehurst, N.C., near his vacation home. He was 76.

The Albany Times Union of New York first reported his death. The cause was a staph infection.

Mr. Constantine began his career as a deputy sheriff and later became a New York state trooper. He held almost every rank in uniform and as an investigator before becoming the statewide police superintendent in 1986.

He led sweeping crackdowns on the drug trade throughout New York before being named to head the DEA in 1994 during the Clinton administration. The DEA had 3,500 agents operating in the 50 states and in more than 50 countries when Mr. Constantine became the administrator.

During his first year, the DEA ran Operation Dinero, in which a fake bank was created in the British West Indies to catch drug dealers laundering their profits. The operation resulted in more than 90 arrests and the seizure of nine tons of cocaine as well as major artworks that had been in the hands of drug lords.

DEA Administrator Thomas A. Constantine in 1997. (Ray Lustig/The Washington Post)

Mr. Constantine also helped coordinate a program with the Colombian national police to break up the Cali cocaine cartel. Their efforts led to the arrests of the six top Cali drug kingpins in 1995.

The drug pipeline then shifted to Mexico, which became the primary focus of Mr. Constantine’s attention and frustration. When he spoke out in 1996, suggesting that Mexico should try to capture some of its drug lords, Mexican diplomats called his comments “offensive.”

As Mexican drug traffickers stepped up their activities, they used threats, intimidation and wealth to exert greater influence over police and prosecutors. DEA agents came under threat in Mexico.

In February 1999, Mr. Constantine testified before a Senate panel on drug enforcement, saying that Mexican “drug mafias” were the most serious criminal danger to the United States that he had seen in 40 years.

“What is frustrating is that we know who the 20 or 25 top drug dealers in Mexico are,” he told The Washington Post, “but the Mexican law enforcement is so weak it seems unable even to find them, never mind arrest them or extradite them.”

Mr. Constantine soon found himself at odds with various economic and diplomatic initiatives of the Clinton administration. Two days after he delivered his critical testimony on Capitol Hill, Secretary of State Madeleine K. Albright said Mexico was cooperating fully with U.S. drug enforcement efforts.

Within three months, Mr. Constantine resigned from his post as the country’s chief drug enforcer.

“I watched that situation for five and a half years, and every year it became worse,” he told the New York Times in 1999. “Everyone would say, ‘Your facts are correct, but there are bigger policy issues involved.’ ”

Thomas Arthur Constantine was born Dec. 23, 1938, in Buffalo, where his father worked at a brewery.

He began his police career in 1960 as a sheriff’s deputy and became a New York state trooper two years later. He graduated in 1970 from what is now Buffalo State University and received a master’s degree in criminal justice in 1977 from what is now New York’s University at Albany.

When Mr. Constantine was leading the New York State Police in 1993, he helped organize a multi-state sting operation with federal agencies that led to the arrest of 57 major drug dealers. But his police agency was also troubled by an evidence-tampering scandal, including the falsifying of fingerprints. Several law enforcement officials went to prison on perjury and other charges.

“The idea that a sworn police officer in any agency, but in this agency, would be framing people with fabricated evidence — it’s just unbelievable,” Mr. Constantine said.

During his four years at the helm of the DEA, the agency added more than 1,000 agents, its budget increased from $700 million to $1.3 billion and a $29 million training center was built in Northern Virginia.

Mr. Constantine also stepped into the culture wars in 1997, when he accused the CBS sitcom “Murphy Brown” of “trivializing drug abuse” when its lead character, played by actress Candice Bergen, smoked marijuana to ease nausea during chemotherapy.

“I am extremely troubled that at a time when teenage drug abuse is doubling,” Mr. Constantine said, “a television show of the caliber of ‘Murphy Brown’ would portray marijuana as medicine. It is not medicine.”

Survivors include his wife of 55 years, the former Ruth Cryan of Niskayuna, N.Y.; six children; a brother; 15 grandchildren; and three great-grandchildren.

After leaving the DEA, Mr. Constantine spent more than three years directing an effort to revamp the Royal Ulster Constabulary, the British government’s police force in Northern Ireland. He also taught at the University at Albany, where he launched a training program for police executives.

Mr. Constantine admitted that his tough talk about Mexican drug trafficking didn’t always sit well with some people in Washington.

“Only in Washington and in these types of diplomatic circles are you sanctioned for telling the truth and rewarded for not telling the truth,” he told the Chicago Tribune in 2000.

“Look, you’re talking to a career cop who didn’t go to the Georgetown University School of Foreign Relations. My job was to protect the citizens of the United States, and if they were upset with what I said, so be it.”