LOS ANGELES, JAN. 6 -- A federal grand jury today indicted one American and eight Mexicans, including multimillionaire drug trafficker Rafael Caro Quintero and three former Mexican police officers, in connection with the 1985 kidnaping, torture and murder of U.S. Drug Enforcement Administration agent Enrique Camarena Salazar.

The indictment superseded an earlier, sealed indictment against just three suspects, and Assistant U.S. Attorney Jimmy Gurule said investigations were continuing to identify and find "many, many more" persons thought to be involved in the crime.

The murder of both Camarena Salazar and a Mexican pilot, Alfredo Zavala-Avelar, after interrogation and torture in a Guadalajara suburb, enraged U.S. officials and became a sore point in official U.S.-Mexican relations after the involvement of corrupt Mexican police officers became known. Although three of the accused drug dealers indicted today are in U.S. custody on other charges, others in the scheme are either at large or in Mexican custody, and the prospect of their being extradited to the United States is uncertain.

DEA Administrator John C. Lawn told a news conference here that international drug investigations require that "we depend on the integrity of our law enforcement counterparts" in other countries. In the Camarena Salazar case, he said, "that mutual trust failed."

Asked repeatedly if they could trust Mexican authorities to try to convict the murder suspects they now hold, both Lawn and U.S. Attorney Robert C. Bonner said they were confident justice would be done. Bonner said the four men now in Mexican custody, including Caro Quintero, also violated Mexican law and that he expected they would be punished severely there, even if they were not extradited.

Named in the 15-page, five-count indictment were Raul Lopez-Alvarez, an American said to be part of Caro Quintero's marijuana- and cocaine-trafficking organization, and six Mexican members of the group besides Caro Quintero: Ernesto Fonseca-Carrillo, Rene Martin Verdugo-Urquidez, Sergio Espino-Verdin, Ines Calderon-Quintero, Jesus Felix-Gutierrez and Albino Bazan-Padilla.

Also named was Armando Pavon-Reyes, at the time of the murder a high official in the Mexican federal judicial police. The Mexican government initially assigned Pavon-Reyes to head its investigation of the kidnaping and murder of Camarena Salazar and Zavala-Avelar.

Later, when it was discovered he had helped Caro Quintero escape arrest, he was arrested and convicted of taking a bribe. He was released more than a year ago after serving a brief jail sentence on that charge, but before U.S. officials had gathered sufficient evidence to charge him in connection with Camarena Salazar's murder. He and Calderon-Quintero "are fugitives," Bonner said, while the others are in custody.

The other two former Mexican police officers are Lopez-Alvarez and Espino-Verdin, who are among five men charged with being principals in the kidnaping and murder. Others are charged as accessories after the fact or for helping Caro Quintero escape from Guadalajara and seek refuge in Costa Rica.