A lawyer who accused top generals and relatives of President Ernesto Zedillo of narcotics graft as a defense tactic in the corruption trial of the Mexican government's drug czar was killed as he drove away from his Guadalajara offices late on Tuesday.

The lawyer, Tomas Arturo Gonzalez Velazquez, 43, died in his car after he was shot with a 9-millimeter pistol, the authorities said.Publico, a Guadalajara newspaper, said the killer "had short hair and looked like a soldier." Some witnesses said he acted with the confidence of a police officer.

Gonzalez was the architect of the defense of the drug czar, Gen. Jesus Gutierrez Rebollo, after his arrest in February 1997 on charges that he abused his powers to protect one of Mexico's largest traffickers.

In several court appearances, Gonzalez portrayed the general's arrest as part of a vast power struggle within the military, in which some top commanders were collaborating with a trafficking group based in Tijuana and others with a rival group based in Ciudad Juarez.

He also argued, without providing evidence, that Zedillo's brother-in-law had formed ties with a major methamphetamine trafficker.

Mexico's defense minister, Gen. Enrique Cervantes Aguirre, barely contained his fury in several public denials of Gonzalez's charges. But in a classified report presented in February to Attorney General Janet Reno, American officials seemed to give credence to some of the accusations that were first lodged publicly by Gonzalez.

The report argued that the arrest of Gutierrez Rebollo was part of a broader web of top generals and traffickers than the Mexican government has acknowledged.

Gutierrez Rebollo, who was held for 14 months at the high-security Almoloya Prison west of Mexico City, was convicted of illegal possession of arms and abuse of authority and sentenced in January to 13 years' imprisonment. Parallel military courts-martial and civilian trials on bribery and drug charges continue.

Before the general's arrest, Gonzalez belonged to a small group of current and former police officials and military subordinates who were the general's closest collaborators during his years as commander of a vast army region based in Guadalajara.