María de las Mercedes Bernardina Bolla Aponte de Murano was born on May 20, 1930, in Corrientes, Argentina. Not much is known about her childhood or family background. She grew up in a time when Argentina was facing various social and economic challenges. The details of her early education and life in her youth are not well documented.

As she matured, she lived in Buenos Aires, where she became known by the nickname Yiya Murano. She had a reputation in her community, but again, specific details about her relationships and personal life during her early adulthood are sparse. The lack of clear records makes it difficult to paint a full picture of her early years.

Yiya Murano's life took a significant turn in the late 1970s when she became involved in serious legal issues. Before this period, her life was relatively quiet, and she engaged with people in her neighborhood. However, her later actions overshadowed her earlier life.

She lived in a neighborhood where she was known to borrow money from acquaintances. Some reports indicate that she had a complex relationship with her neighbors, which later became crucial in the events that unfolded in her life. The absence of thorough records from her early life contributes to the enigma surrounding her background.

In early 1979, a disturbing pattern of sudden deaths began to unfold within Yiya Murano's inner circle. On February 10, 1979, Murano's neighbor Nilda Gamba died suddenly under suspicious circumstances. Just nine days later, on February 19, Leila "Chicha" Formisano de Ayala—another friend to whom Murano owed money—also died suddenly. Both deaths initially appeared natural, but investigations later revealed signs of cyanide poisoning in their bodies. In both cases, Murano was known to have been the last person in contact with the victims, and she had significant financial debts to each of them.

The pattern repeated on March 24, 1979, with the death of her cousin, Carmen Zulema del Giorgio de Venturini. Zulema died after allegedly falling down the stairs in her building on Hipólito Yrigoyen Street. Her death was initially attributed to cardiac arrest. However, key observations began to raise suspicions: the building’s doorman reported that Murano had visited with a package of petit fours and requested a copy of Zulema’s apartment keys, claiming she needed a notebook to contact relatives. After entering the apartment, Murano was seen leaving quickly with a jar and documents. Shortly after Zulema’s death, her daughter discovered that a promissory note worth 20 million Argentine peso ley had disappeared.

An autopsy later revealed cyanide in Zulema's body. Investigators found traces of the poison both in the petit fours and in the jar Murano was seen taking. Authorities began to connect the dots, and on April 27, 1979, Murano was arrested at her home on Mexico Street in Buenos Aires. While incarcerated, she was found unconscious under unknown circumstances and underwent surgery in prison, including the removal of a lung.

Despite overwhelming forensic evidence, Murano continued to proclaim her innocence. She was eventually convicted in 1985, the same year as Argentina’s historic Trial of the Juntas, a coincidence that placed her conviction in the shadows of broader national news. Her famous quote, “I never invited anyone to eat,” became a darkly ironic denial, as all three victims had either received or consumed food items traced back to her.

After serving 16 years in prison, Murano was released due to her advanced age and declining health. She spent her final years in an elderly care facility. In a macabre gesture, she reportedly sent chocolates to the judges who approved her release, a callback to her method of poisoning via sweets. Her case captivated the nation and inspired dramatizations, including her feature in the book Mujeres Asesinas and an episode of the Argentine TV series based on it. In a twist of unsettling closure, Murano herself appeared at the end of the TV recreation to once again proclaim her innocence on national television. Yiya Murano died on April 26, 2014, at the age of 83, having never formally confessed to the murders.