Two Americans killed waiting to cross into the U.S. near San Ysidro may have been killed by a man seeking revenge.
Mexican authorities originally thought the execution-style killings of Sergio Salcido Luna, 25, and Kevin Joel Romero, 28, were connected to drug cartels. The men were shot in the head, arms and body as they sat in a work truck with California license plates before dawn Monday.
On Tuesday investigators dropped that theory, saying they had a strong lead in the case.
Friends said Salcido caught his girlfriend having an affair with another man a few months ago and beat that man to a pulp. When Salcido and the man were sitting in the back of a Tijuana police car, the man told Salcido he would kill him someday, according to friends who did not want to be identified.
The state attorney general's office said Tuesday that investigators had discounted drugs as a possible motive in the killings, and were looking into possible motives related to the victims' families or work.
Romero's aunt says the men would never get involved in drugs.
"It's completely the opposite. That's why I want things cleared up and for justice to be served. That's all I want. I don't want vengeance. I want justice,"said Marcela Romero.
Romero grew up in San Diego, but moved to Tijuana because it was cheaper to live there.
Salcido was a professional fighter who began his career in mixed martial arts in Bakersfield before moving to San Diego to train.
The men were crossing around 2:40 a.m. as they usually did to beat the long lines that form later in the morning when thousands cross to go to work or school on the U.S. side. Romero's parents live near the border on the U.S. side and the men would go there to sleep before heading in to work.
The men worked for West Coast Beverage Maintenance on Morena Boulevard in San Diego. Owner Matt Pelot told NBCSanDiego that Salcido and Romero were hardworking people.
"They were always asking for more hours,"Pelot said. "Kevin just got married and adopted his wife's son."
At "The Arena" in Midway where Salcido trained and Romero lifted weights, news of the killings left trainers and fighters in a daze.
"Just sad man, just shocked," said trainer Cosmoe Cala. "He (Salcido) was a young guy, full of life."
Mexican investigators won't reveal any information about the suspect they are looking for, but friends believe the killer is a gang member from Los Angeles.
More than 94,000 people pass through Tijuana's two border crossings into the San Diego area and about half of them are going to work or school, according to San Diego Association of Governments.