2 Slayings May Have Colosio Link : Probe: Sheriff’s Department seeks to determine if men shot on I-5 had ties to assassinated Mexican candidate. That country’s government denies any connection.

Los Angeles County Sheriff’s detectives are investigating a possible connection between the shooting deaths of two men on a Southern California freeway in February and the assassination in March of Luis Donaldo Colosio, Mexico’s ruling party presidential candidate, authorities said Thursday.

Mexican officials, however, denied any connection between the two slain men and the killing of Colosio in a Tijuana shantytown March 23. One federal official blasted such assertions as “false and irresponsible.”

Nonetheless, Sheriff’s Department investigators suspect that the two men, one of whom was carrying credentials purportedly issued by the office of the president of Mexico, worked as security guards for the Colosio campaign and maintained residences on both sides of the border. Although the investigation, including interviews of witnesses in the United States and Mexico, suggests that the double murder may be related to the subsequent slaying of Colosio, the motive remains unclear, deputies said.

“We have not confirmed as yet if there is a connection between the assassination of Mr. Colosio and that shooting,” said Sheriff’s Sgt. Noel Lanier. “Homicide investigators are aggressively working that case and taking any leads and rumors and putting the case together.”

The Sheriff’s Department investigation adds a strange twist to the already murky Colosio case. Although a gunman and three alleged accomplices have been charged with killing the candidate, the Mexican government’s investigation has bogged down amid unanswered questions and conspiracy theories pointing to politicians, drug traffickers and possibly both.

Three of the suspects in Colosio’s murder were volunteer security guards provided by his political party for crowd control. Colosio’s personal bodyguards were army officers who serve in the Mexican equivalent of the Secret Service, as well as other members of the federal security forces.

Manuel Salvador Gonzalez, 37, and Antonio Trejo, 35, were gunned down by five shots from a passing car as they drove in a Cadillac on the Golden State Freeway, Interstate 5, near Gorman. A detective described the slayings as the work of professional assassins.

Based on interviews with the victims’ families and others, authorities believe Salvador was “an official in the Mexican government and in the political party PRI (the Institutional Revolutionary Party),” according to a detective who asked not to be identified. Salvador and Trejo were both working security for the Colosio campaign, probably as bodyguards, the detective said.

Among the documents found on the bodies was a letter of introduction purportedly bearing the signature of Jose Maria Cordoba Montoya, a powerful former aide to Mexico’s President Carlos Salinas de Gortari. Also found were documents indicating that Salvador was “in charge of special investigations for the government of Mexico,” said a source close to the investigation. U.S. authorities said they are operating under the assumption that the documents are legitimate.

But a Los Angeles-based spokesman for the Mexican federal attorney general’s office said the credentials were obviously false and that the men did not work for the government. The official, Juan Miguel Ponce Edmondson, said that the murder appears to be drug-related and that the Cadillac is linked to an investigation of methamphetamine trafficking in Los Angeles.

“It was an incident related to drug trafficking,” Ponce said.

Mexican investigators examined the credentials at the request of sheriff’s deputies shortly after the double murder and concluded that the identification documents were counterfeit, Ponce said.

In addition, the PRI issued a statement from Mexico City saying that Salvador did not work for the political party or for the candidate’s security force, denying a report that hewas a chief of security for Colosio.

Salvador “never occupied any post or commission in the PRI,” the communique said, adding that on the date of the murder, the plans for Colosio’s trip to Tijuana had not yet been made. “Therefore, any possible connection between the two events is unfounded.”

Sheriff’s deputies, meanwhile, said the Mexican government has not cooperated with the investigation.

“The Mexican government, they are telling us this individual did not exist and neither did the function he carried out,” the investigator said of Salvador. “Our problem is we can’t confirm any of this. The family tells us one thing and the Mexican government is telling us the other.”

U.S. authorities said the two victims both had homes near Guadalajara in the Mexican state of Jalisco, but also maintained residences near Los Angeles.

A relative of Salvador in Glendale declined to be interviewed, but she said a Chevrolet Suburban outside the apartment house had belonged to him. The vehicle was decorated with three PRI bumper stickers.

There is no hard evidence that the two victims were involved in drug trafficking, detectives said, although they believe politics and drugs may have been involved.

The Cadillac driven by Trejo was traveling at 75 m.p.h. south on the Golden State Freeway on Feb. 27 when another vehicle pulled up alongside and fired five shots from a 9-millimeter weapon, authorities said. Because all five shots hit the victims in the neck and head, authorities suspect they were professional assassins.

“There was not a single mark on the outside of the car to indicate a stray round,” said one source. “We’re talking about someone who is really a good shot, a professional. This was definitely an assassination. Whoever did it knew what they were doing.”

Times staff writer Patrick McDonnell contributed to this report.