Alberto Sierra, aged 42, admitted guilt on Friday in a Miami-Dade court for the murder of his estranged wife and her two young daughters nearly 14 years ago. The case now moves directly to the penalty phase where a jury will determine whether he receives the death penalty or life imprisonment.
Appearing in court in an orange prison jumpsuit, Sierra stood before Judge Marisa Tinkler Méndez of the Miami-Dade Circuit Court and entered his guilty plea without any plea deal with the prosecution, as reported by the Miami Herald.
When the judge reminded him that he faced the possibility of execution, Sierra replied tersely, "Yes, ma'am. It's been 14 years, so..."
The victims of this horrific crime were Gladys Machado, 29, and her daughters, Julia Padrón, 8, and Daniela Padrón, 4.
The murders occurred on November 10, 2012. Three days later, a neighbor discovered their bodies hidden in a closet at their Flagami residence, located in the 7300 block of Northwest Fourth Street.
According to his confession to detectives, Sierra accompanied Machado and the girls to the Mall of the Americas in her golden Nissan Altima. During the drive, Machado received a call from another man, prompting Sierra to stab her inside the vehicle. He then drove them to their home, locked the children in a room, and suffocated Machado with a plastic bag.
The arrest affidavit, as cited by NBC Miami, revealed that Sierra also sexually assaulted Machado, later removing one of the girls from her room to suffocate her, repeating the act with the other while she slept.
DNA evidence collected from Julia matched Sierra, and his fingerprints were found at the crime scene.
Machado and Sierra shared a history of domestic violence and had recently separated before the murders. Machado had moved in with her grandmother in Homestead, while Sierra resided with his mother in Kendall. On the night of the killings, Machado's six-year-old son was with his grandmother, which likely saved his life.
The victim’s car was discovered nine days post-murders, parked in reverse among bushes at the Calusa Club Apartments complex, directly across from Sierra's mother's home, with blood on both seats. Police indicated the car was positioned to obscure the license plate.
Sierra had been released from prison just five months before the murders for violating probation when a weapon was found at his home. He had previous convictions for drug and weapon offenses. Additionally, the Department of Children and Families had investigated him after Julia told a teacher that her stepfather bit her, though Miami-Dade police deemed it a "playful" incident and no charges were filed.
Sierra was charged with three counts of first-degree murder, three counts of kidnapping, two counts of corpse abuse, and one count of burglary with assault.
In Florida, the death penalty is applied if at least eight of the 12 jurors recommend it, following a 2023 law that removed the unanimity requirement. Jury selection for the sentencing phase is set for August 17, where the chosen 12 citizens will decide Sierra's fate—life in prison or death for ending three lives in one night.
Key Aspects of Alberto Sierra's Case
What charges does Alberto Sierra face?
Alberto Sierra is charged with three counts of first-degree murder, three counts of kidnapping, two counts of corpse abuse, and one count of burglary with assault.
When are the jury proceedings scheduled?
Jury selection for the penalty phase is scheduled for August 17, where 12 jurors will determine if Sierra receives the death penalty or life imprisonment.
What led to the discovery of the victims?
A neighbor found the bodies of Gladys Machado and her daughters in a closet three days after the murders.