He had been taken into custody after leading officers on a high-speed chase. The female passenger that was with him apparently told authorities during interviews of the locations of the bodies in Mount Baldy and Chino.
These interviews led authorities to realize that Caballero could possibly be responsible for multiple murders.
The first victim's body was found Saturday in Chino, and that person has been identified as 29-year-old David Arthur Padilla of El Monte. His body was located under a freeway overpass in the 3800 block of Walnut Avenue atop some railroad tracks. It appeared that he died from some sort of trauma to the upper body.
Victoria Padilla still cannot say exactly how her husband was killed.
"It's still an on-going investigation, so they're not telling me anything. So all I know is that my husband's body was found here and he's not coming home," she said.
Family members say Padilla had simply vanished on Thursday night. Police were led to his body after arresting a man in Pomona over the weekend.
"The guy just did not have a heart or he didn't care about life in general. He took somebody's life that's a big loss to my sister-in-law and her baby," said Richard Garza, the victim's brother-in-law.
Authorities aren't saying how all the victims are connected, but Garza believes Caballero was an active gang member who was related to Padilla.
"Whatever happened, it was wrong because I don't think he did harm to anybody to deserve what he had coming," said Garza.
Victoria Padilla says she never met the suspect. She just hopes justice will be served for this father of four.
"He's going to get what he deserves, and that's all I can really say," said Victoria about Caballero.
"I leave it to god's hands," she added.
The body of Caballero's second possible victim was also found Saturday night in Mount Baldy.
"At about 7 p.m. sheriff's homicide detectives went out to the 1.34 marker in Mount Baldy to investigate the circumstances of a woman who was found there deceased," said Jeffrey Gordon of Los Angeles Police.
According to the coroner, that woman's body was found buried somewhere off of Mount Baldy Road.
It is still unclear how Caballero may be linked to all three of these deaths.
Caballero is being held on $3 million bail, and he is expected in court Tuesday.