Neonatal Nurse ‘Playing God’ Injected Infants With Chemicals — Killing 5. Now She’s Behind Bars for Life

In just three months at an Argentinian neonatal unit, five babies died and eight more went into crisis — each tied to the same nurse’s shift.

In June 2025, a jury in Córdoba convicted Brenda Cecilia Agüero of five counts of aggravated murder and eight counts of attempted murder after a six-month trial and about 10 hours of deliberation, according to the Buenos Aires Times, El País and the Buenos Aires Herald.

She was sentenced to life in prison at Bouwer Penitentiary, with parole eligibility after 35 years.

According to the outlets, she has maintained her innocence while behind bars, claiming she was a scapegoat for systemic failures at the hospital.

“She was playing God. She decided who lived and who died,” attorney Daniela Morales Leanza said while describing the pattern and motive in court, the Buenos Aires Herald reported.

Per the outlet, court-presented psychological and psychiatric evaluations described narcissistic and eccentric traits, lack of empathy and satisfaction in others’ suffering, and said her motivation included seeking recognition and advancing her career. 

The first emergency tied to the case was recorded in March 2022 at Hospital Materno Neonatal Ramón Carrillo, where a previously stable, healthy newborn developed sudden cardiorespiratory distress, El País reported.

In the following weeks, other healthy infants experienced acute respiratory failure or cardiac arrest without a clear medical cause, and two neonatologists made a judicial complaint that prompted a formal probe, per the outlet.

A pivotal stretch came on June 6–7, 2022, when two babies died and two others nearly died during a single shift, the Buenos Aires Herald reported. According to the outlet, staff and families later described needle marks and, in one case, a “prick in the back,” leading doctors to convene to question medications and procedures. 

Prosecutors argued Agüero injected potassium and insulin into the infants, provoking lethal arrhythmias, El País and the Buenos Aires Times reported.

According to the outlets, autopsies in two deaths found hyperkalemia consistent with injected potassium, and experts testified that insulin levels in some of the newborns were so extraordinarily high they are not even seen in adults with advanced pancreatic cancer.

This, according to experts, indicated administration with no medical indication, per the Herald.

One mother testified that she saw Agüero take her baby, turn away, and return the child shortly before the infant stopped breathing, the Buenos Aires Herald reported, adding that eight babies survived overall. One survivor has irreversible neurological damage doctors linked to insulin, and another developed severe scoliosis after a potassium injection in the back. 

Agüero was arrested and charged on Aug. 19, 2022, according to La Nación.

“I am not that monster that they have created in the media. I understand the pain of the mothers, but I am not the serial killer that they made everyone believe,” she said in her final statement in court, per the Buenos Aires Herald.

The trial also resulted in five other convictions of hospital and provincial health officials for concealment and omission-of-duty counts, the Buenos Aires Times and Chequeado reported.

Per those outlets, former hospital director Liliana Asís and former administrative sub-secretary Alejandro Escudero Salama received 64 months behind bars, former neonatology head Martha Gómez Flores received five years, former patient-safety coordinator María Luisa Moralez received five years that was suspended and former provincial health secretary Pablo Carvajal received a suspended four-year sentence.

All five remain free under bond conditions until the judgment is final.