At the time of Hernandez's arrest, he was a registered sex offender on parole from an 18-year sentence after admitting in court to a burglary where a woman was raped.
Jurors at his 2002 capital murder trial learned Hernandez also was linked by DNA to the 1994 sexual assaults and slayings of Sarah Gonzales, 13, and her cousin, Priscilla Almares, 12, in the same San Antonio area where Rosado was abducted.
"We're not cruel people, we don't want to have to watch somebody die," Brenda Ayala, Almares' sister, said after witnessing Hernandez's execution. "It doesn't give us happiness at all. If anything, I feel sorry for his family and they're going to have to feel what we felt when we lost our loved ones."
He was a suspect in the killings of two 15-year-old girls west of San Antonio as well. They disappeared within days of the Gonzales and Almares slayings.
Hughes, set to follow Hernandez to the death chamber, was convicted of the 1988 stabbing deaths of Shandra Charles, 15, and her 3-year-old cousin Marcell Taylor. They were attacked in a field behind an apartment complex where Hughes lived.
Hughes, 46, claims police planted evidence and coerced his confession. He and his appeals attorney, who Hughes has sought to fire, have multiple appeals pending in state and federal courts to put off Thursday's planned execution.
Police responding to a passer-by's call about a body in the field found Charles still alive. The teen told an officer that "Preston" had tried to rape her. Authorities went to the nearby apartments and determined that Hughes was the only resident with that first name.
Hughes, who knew Charles through a friend, denied any involvement in her death. However, he made statements while in police custody that implicated him, one of his trial attorneys recalled this week.
"We did what we could with what we had. ... I could say he convicted himself," defense attorney Ellis McCullough said.
But Hughes has insisted he is innocent. "The fact is I didn't kill anyone," he told The Associated Press last month from death row.