Juan Ramon Segundo Meza was born in California on January 25, 1963. When he was about one year old, his family moved to El Paso, Texas. They left California to escape Segundo's abusive father. In El Paso, Segundo lived with his mother and two brothers in a small apartment that did not have running water. Life was challenging for them. Sometimes, Segundo's mother would leave the children alone for several days. At times, his eight-year-old brother had to search through trash bins for food to eat. There was a time when the brothers were placed in an orphanage but later returned to their mother.

Segundo's mother remarried a man who struggled with alcoholism. This man was also abusive toward Segundo and his brothers. According to Segundo's brother, when Segundo was a small child, he fell down some stairs and hit his head. After that accident, Segundo started to act different. His brother described him as "kind of slow" and said he was often "always in a daze."

Juan Ramon Segundo Meza was involved in the killing of Vanessa Villa, an 11-year-old girl, on August 3, 1986, in Fort Worth, Texas. That day, Vanessa had gone to work at a flea market in Dallas. When she returned home later in the evening, her mother and siblings were out running an errand. Durante este tiempo, Segundo entered the family's home. When Vanessa's mother returned, she found her daughter unconscious in her bedroom. Vanessa died at the hospital early on August 4.

On October 6, 1987, Segundo assaulted a woman in her home. She woke up to find him fondling her. When her daughter started to wake up, Segundo fled. The woman later identified him as a former coworker. In June 1988, he was sentenced to ten years for burglary in connection with this incident.

In 1990, Segundo attempted to choke another woman in her home after entering it while unclothed. The victim recognized him, leading to more prison time. From 1991 to 1993, Segundo remained in prison for this crime.

Through DNA testing in 2010, he was linked to three other murders that occurred in the mid-1990s. These cases involved Melissa Badillo, Francis Williams, and Maria Reyna Navarro. Each of these women was murdered in separate incidents between 1994 and 1995.

In 2005, while serving a different prison sentence, Segundo's DNA was matched to the crime scene of Vanessa Villa’s murder. A trial followed, where he was found guilty of her murder and was sentenced to death in 2006.

Over the years, appeals were made regarding his conviction and sentence. While he was initially set to be executed in 2018, concerns over his intellectual disability led to a stay in the execution. On May 25, 2022, his death sentence was changed to life in prison. He is currently held at the Coffield Unit in Tennessee Colony and is eligible for parole in 2026.