Fernando Eros Caro Jr. was born on December 3, 1949, in Brawley, California. He was the first of eight children in a family of migrant workers. His parents were of Mexican-Aztec and Yaqui descent. Growing up, Fernando spent a lot of time working in the fields alongside his family. This work was hard and often dangerous. He faced a difficult home life, as both of his parents reportedly beat him frequently.

In school, Fernando was given the nickname "Stinky." This name came from the smell of pesticides that clung to his clothes from his time spent working in the fields. Despite these challenges, he completed his education. After finishing high school, he attended San Diego State University, where he majored in civil engineering. However, he eventually dropped out of university.

Seeking a different path, Fernando enlisted in the Marine Corps. He trained hard and became an officer, flying attack helicopters during his service. After his honorable discharge, he faced a series of life choices that would lead him down a dark path. In 1976, he committed his first crime when he kidnapped a law clerk.

On February 3, 1979, 8-year-old Victoria "Toria" DeSantiago left home to buy bread. She was with her 3-year-old sister Eva Marie and their dog. After they bought the bread, the girls realized the dog was missing and went to look for it. They met Fernando Eros Caro, who offered to help. Instead, he kidnapped them and drove away. Hours later, he released Eva Marie after abusing her, but he continued to hold Victoria. He took her to a field where he hurt her and then killed her. Victoria's body was discovered a few days later in a dry creek bed.

On August 20, 1980, 15-year-olds Mark Hatcher and Mary Booher went on a bike ride. They encountered Caro, who shot Mark and took Mary away in his truck. He crashed into another truck shortly after, where the drivers attempted to stop him. Caro shot at them but they managed to escape. Later that night, he killed Mary in a grove by shooting her in the head.

Afterwards, police began investigating the attacks. The drivers of the truck provided a description of Caro and his vehicle. This led police to Caro's workplace a few days later. When officers approached him, he tried to run off but was quickly caught. His coworkers were shocked, having thought he was a quiet and nice man. Soon after his arrest, Mary’s body was found. Caro was charged with two counts of murder and other related crimes.

In the summer of 1980, two bodies of teenage girls were found in an orchard. They had been bound and shot. The investigation suggested these murders might also involve Caro because a gun he owned was the same caliber as the one used in the girls' deaths. However, he was not charged in that case due to lack of evidence.

Caro's trial focused on the murders of Mark and Mary. He was found guilty, sentenced to death, and appealed his sentence multiple times. His death sentence was later changed to life imprisonment. In 2009, DNA linked him to Victoria's murder, and the state planned to file new charges against him.

Caro spent many years on death row until January 28, 2017, when he was found dead in his prison cell. An autopsy suggested he died of natural causes.