In the space of about six weeks in early 1979, three women in Buenos Aires who had handed their savings to the same acquaintance died one after another. Each death was first put down to natural causes. The acquaintance was Yiya Murano, a lawyer's wife who lived in the Monserrat district near the city center and who had been taking money from friends, neighbors and relatives on the promise that she could make it grow. After the third woman died, her daughter went to the police. An autopsy found cyanide, the other two women were exhumed, and on April 27, 1979, Murano was arrested.
The case went through two very different judgments. In June 1982 a trial judge acquitted her of everything for lack of proof and she walked free. In 1985 an appeals chamber reversed that ruling and sentenced her to life imprisonment for three aggravated homicides by poisoning and for fraud. The sentence was later reduced, and she left prison in the 1990s. She spent the rest of her life giving interviews and television appearances in which she denied killing anyone. She died in a Buenos Aires care home in 2014.
She was born María Bernardina de las Mercedes Bolla Aponte on May 20, 1930, in the city of Corrientes, in northeastern Argentina, according to Infobae, the Buenos Aires Herald and an account distributed by the news agency Noticias Argentinas. Some reports give her names in a different order, as María de las Mercedes Bernardina. Her family soon moved to Buenos Aires, La Gaceta of Tucumán reported. She grew up in a military family of modest means, the Buenos Aires Herald wrote. Infobae reported that her father was a lieutenant colonel, and the Noticias Argentinas account says her brother was an army officer who rose to general, which it offers as a possible reason she did not use her maiden name.
She trained as a teacher but never worked as one. According to C5N, her husband wanted her to keep house. In 1953, at 23, she married a lawyer and took his surname, Murano. The Noticias Argentinas account says he died in 1985 and stresses that his death had nothing to do with any crime of hers. They had one son.
The Buenos Aires Herald described a woman who wore jewelry and furs that her husband's income could not have paid for and who presented herself as wealthy. She later boasted of a very large number of lovers, more than 200 in the Herald's account and about 250 in Infobae's, some of them, she said, powerful men. The Herald noted that the figure was never confirmed.
The late 1970s in Argentina were the years of what Argentines called "plata dulce," easy money, under the economic policy of the military government that had taken power in March 1976. Short-term deposits and speculative interest rates were in fashion. Minuto Uno tied Murano's scheme to that climate. She told friends that she had good contacts, as a military officer's daughter, and could quickly double their savings.
Infobae described what she ran as one of the first pyramid schemes in the country. She took money from friends, relatives and neighbors, signed promissory notes for it, and promised them monthly interest. According to the Noticias Argentinas account, her second cousin, Carmen Zulema del Giorgio de Venturini, known as Mema, gave her a modest sum at first and was happy with the returns, then made a second, larger investment that did not pay as promised. Nilda Adelina Gamba, a neighbor, and Gamba's friend Lelia Elida Formisano de Ayala, known as Chicha, also gave her money. Murano began to visit them more often.
Minuto Uno reported that the three women together had given her about 300,000 dollars. C5N and Minuto Uno both reported that one of the notes Murano had signed to her cousin was for 20 million pesos. By early 1979 the payments had stopped, and the women were asking for their money. Murano, according to Minuto Uno, was evasive and nervous when they raised it.
Little has been reported about the three women as people beyond their names, their ties to Murano and the money they had entrusted to her. Nilda Adelina Gamba was a neighbor; C5N gives her age as 64. Lelia Elida Formisano de Ayala, Chicha to her friends, was a family friend, 59 at her death according to C5N. Carmen Zulema del Giorgio de Venturini, Mema, was Murano's second cousin and a mother; C5N gives her age as 64. Her daughter's persistence after her death is what brought the case to light.
Nilda Gamba was the first to die. According to the Noticias Argentinas account, she fell ill on Saturday, February 10, 1979, after having tea with Murano that afternoon, and was seen by a doctor. Murano offered to look after her. Gamba died early the next morning, February 11.
The doctor who had treated her refused to sign a death certificate, saying he had not been the last to attend her. A doctor from the funeral home signed it instead, for a tip, according to the Noticias Argentinas account and Infobae, and gave the cause as a non-traumatic cardiac arrest. Because the death was certified as natural, there was no autopsy. Diario UNO reported in 2019 that a doctor was later prosecuted, without giving further detail.
The same account records an earlier episode. Some six weeks before her death, Gamba had been out of touch for three days, and her family reported her missing. Police were called, and the episode was put down to a diabetic coma. Murano had been the last person to see her. The account leaves open whether this was a failed first attempt or a genuine diabetic crisis, and no court finding on it was reported.
A few days after Gamba's death, Murano visited Lelia Formisano de Ayala, who was owed money, to reassure her, the Noticias Argentinas account says. The two women had arranged to go to the theater that evening, but when Murano and others went to collect her, no one answered. On February 22, 1979, neighbors called the police, and Formisano was found dead. C5N dates her death to February 19.
Murano had been there before her death, Infobae reported. Once again a funeral home doctor certified a natural death, this time a non-traumatic myocardial infarction, and once again there was no autopsy. The Buenos Aires Herald reported that Murano helped the families of both of the first two women obtain certificates that listed natural causes.
The third death came on March 24, 1979, the third anniversary of the military coup. Mema del Giorgio fell ill and died the same day. Murano had visited her earlier that day with pastries, according to Infobae and Minuto Uno. The Noticias Argentinas account says that Murano arrived as neighbors were helping her cousin, asked whether Mema had said anything before she lost consciousness, and later asked the doctor whether there would need to be an autopsy. C5N described her reaction to the news of the death as theatrical surprise.
This time a relative asked questions. Sorting through her mother's papers, Mema's daughter found that the promissory notes Murano had signed were missing. The building's doorman told her that he had given Murano a key soon after her cousin collapsed, so that she could call the family, which she never did. According to C5N and Minuto Uno, he said she had left carrying papers and a small jar. La Gaceta reported that the paper was later identified as the note for the debt.
The daughter then saw that the other two women had died in much the same way and had also been owed money by Murano. She went to the police. A judge ordered the bodies exhumed and autopsies performed.
The results differed from one body to another, according to the Noticias Argentinas account and Diario UNO. Mema del Giorgio's viscera showed alkaline cyanide, and her death was classified as poisoning. The tests on the other two women, who had been buried in the ground, were inconclusive, because cyanide compounds can form during decomposition and it could not be said for certain whether the poison had been swallowed. Other reports, among them Minuto Uno and La Gaceta, say cyanide was found in all three. Infobae wrote that the autopsy of one of the three confirmed cyanide.
On April 27, 1979, a team from the Federal Police came to Murano's apartment in Monserrat. Minuto Uno reported that she was polite and asked only for a few minutes to dress and fetch a sweater. She was 49. According to C5N, the officers did not explain why they were taking her, and her husband and son, then 13, learned the reason only days later from journalists who came to the house. Her son has also said he was 12 at the time. He later recalled hearing words such as "dollars" and "fixed-term deposit" as reporters explained the case.
Investigators at the time spoke of ten or more possible victims, Infobae reported, although only three cases were ever brought. On June 12, 1979, Judge Diego Perés ordered her held in preventive detention, according to C5N.
The case became known in the press as that of the "Envenenadora de Monserrat," the poisoner of Monserrat. The Buenos Aires Herald wrote that "Yiya" is still used in Argentina as a byword for a poisoner.
Murano was held in the women's prison at Ezeiza, outside Buenos Aires. In 1980 she was found unconscious there and was taken to hospital, where a tumor was removed from her head; Minuto Uno names the hospital as the Pirovano. The Noticias Argentinas account says the same.
The source of the cyanide was never established. La Gaceta noted that buying cyanide would have needed a professional's signature on a prescription and that investigators never found out how she obtained it. A lover of hers was looked at, because neighbors said they had seen him leaving the building by the stairs on the day of one death, but the evidence against him was not enough, La Gaceta reported. Infobae and the Buenos Aires Herald both say police suspected that a third person, perhaps a doctor or a lover, supplied the poison, and that no one was ever identified.
Criminal trials in Buenos Aires were then conducted in writing, without oral hearings, Minuto Uno noted, and appeals were handled in near secrecy. On June 15, 1982, according to C5N, Judge Ángel Mercado, who had replaced Judge Perés, acquitted Murano of homicide and fraud for lack of proof. Other reports date the acquittal only to June 1982. She was released at once.
The Buenos Aires Herald noted that Murano was a reader of Agatha Christie and knew how hard poisoning could be to prove.
The acquittal was appealed, La Capital reported, and the case went to the third chamber, Sala III, of the Cámara Nacional de Apelaciones en lo Criminal y Correccional in Buenos Aires. The chamber overturned the acquittal and sentenced her to life imprisonment for the three homicides, aggravated by poisoning under article 80, subsection 2, of the Penal Code, together with fraud, which C5N reported as three counts in "material concurrence." Under the Penal Code, Minuto Uno pointed out, homicide by poisoning carries only one possible penalty, life imprisonment.
Accounts differ on the date of the ruling. C5N gives May 16, 1985, as the day the chamber reversed the acquittal. The Noticias Argentinas account, Diario UNO and La Capital of Rosario date the life sentence to June 28, 1985 (La Capital to June 1985). Minuto Uno describes June 28, 1985, as the day the chamber notified its final decision, rejecting an extraordinary appeal and making the life sentence final. Diario UNO's 2019 account names the three judges of Sala III as José Massoni, Oscar Ocampo and Pablo Laoumugne.
By then, the Noticias Argentinas account notes, the country's attention was on the trial of the former military juntas, and Murano had been largely forgotten. Minuto Uno reported that police could not find her at home or at the places she was known to go, that she was reported as a fugitive for a few days, and that she then gave herself up. She was about 54 when she went back to prison, according to C5N. "I never invited anyone to eat," she said, in the words reported by several outlets.
How long she then stayed in prison, and when she left, is told differently in different accounts. Infobae and the Buenos Aires Herald say she was released in 1995 after a reduction of her sentence and the "dos por uno" law, the "two for one" rule that counted each day of pretrial custody beyond two years as two days, and that she served about 13 years in all. La Gaceta gives the release date as November 20, 1995, and La Capital as November 1995. C5N reported that a commutation and a pardon from President Carlos Menem freed her in 1995. Diario UNO's 2019 account says Menem commuted the sentence in 1993 and that she served about nine years, released on parole. The Noticias Argentinas account says she served 16 years, in two periods. Diario UNO's 2025 account gives 16 years and a release in 2002. The Buenos Aires Herald itself observed that its sources do not make clear when the 13 years began.
According to Infobae and the Noticias Argentinas account, Murano sent a box of chocolates to the judges involved in her release as thanks. Minuto Uno reported a version in which the court staff who calculated her sentence received a tray of pastries that no one touched, and added that some people regarded it as a bad joke in which she had no part.
Once free, Murano courted publicity. She gave interviews, appeared on television and, according to the Buenos Aires Herald, offered her story to newsrooms in person. Infobae reported that she was paid for some interviews and said she would sell "the truth of the case" for money or a lunch and would otherwise take it to her grave. The Herald recounted a story that she claimed to keep an envelope holding the whole truth, available for a fee, and that a journalist who glimpsed inside it while she signed an autograph saw that it was empty. A year after her release she became a fashion columnist on the television program La Hoguera, La Gaceta reported.
She was twice a guest at the lunch table of the television host Mirtha Legrand, Infobae reported; the Noticias Argentinas account dates one invitation to 1998. She arrived with pastries as a gift. Legrand joked about her diet and sent them to the production staff, according to Infobae; other accounts say Legrand declined them. The Herald described the host as seeming to hold back a laugh. Murano's son later criticized the studio audience for applauding when she was introduced, C5N reported.
In all of this she maintained her innocence. She denied that the women had been poisoned at all and argued that the doctor who had tried to revive one of them by mouth would have died too, Infobae reported. The only charge she would accept was that she had been a moneylender. "Murderers never tell the truth," she told the journalist Rodolfo Palacios in one of more than ten interviews, according to Infobae. In a 2006 interview on Radio 10, reported by Infobae, she said she had worked with money but killed no one, and that the only two people she had killed were her mother and her first husband, who, she said, could not bear her unjust imprisonment. She said she had first been accused of 10 or 15 murders, and that the media had claimed the poison was in pastries and then in chocolates. She said the pastries she took to her cousin were never touched.
She married again more than once. The Buenos Aires Herald reported that one later husband was an elderly, blind former newspaper proofreader, and that his daughter alleged that Murano had poisoned him for his pension and savings and had tried to poison her as well. Minuto Uno reported that a third husband's daughter threw her out of their home after suspecting she was poisoning them. No charges from either episode were reported.
Her only son, an actor and stunt double, has spoken about his mother for decades. In 1994 he published a book, Mi madre, Yiya Murano, in which, La Capital and Diario UNO reported, he wrote that she had calmly described the crimes to him. Infobae says he has written two books on the case. He has called her a perverse murderer and a psychopath, and he says she told him the poison had been in the tea bags. He has described her as self-centered and theatrical, a woman who used money and sex to gain power, and says a forensic psychiatric report described her as a compulsive liar, according to C5N and the Buenos Aires Herald.
He has also said that when he was about 10 his mother took a cake away from him just before he ate it, and he believes she meant to poison him, Infobae and C5N reported. As an adult, he told C5N, he came to think the killings were aimed at the people who had lent her money. He has said he does not regard her as his mother, and that he was raised after her arrest by a woman who had worked for the family, El Litoral reported.
In 2023 he auctioned the tea set his mother had used, six cups, a teapot, a sugar bowl and a milk jug, with the proceeds promised to an animal shelter in Mar del Plata. He told La Capital that he wanted to turn something bad into something good. Infobae reported an offer of 10,000 dollars.
Murano spent her last years in care homes, in Caballito and then Belgrano according to Infobae, and in La Boca at one stage according to the Noticias Argentinas account and Diario UNO. She had been diagnosed with senile dementia, Infobae reported, and her family kept the press away. A niece told Infobae that she remembered nothing and that the family had decided no one else could see her, Diario UNO reported in 2025.
Most reports date her death to April 26, 2014, in a care home in Belgrano: Infobae, C5N, La Gaceta and Diario UNO. Infobae gives the cause as cardiac arrest and her age as 83. The Noticias Argentinas account and La Capital give June 23, 2014. The Buenos Aires Herald gives her age as 84. Her death drew little press at the time, Diario UNO noted in 2019. Her son was reportedly not told of it.
She was buried in the Chacarita cemetery in Buenos Aires. At the family's request her grave does not carry the name Yiya Murano. "She is buried as Mercedes Bolla," her son said, as reported by Diario UNO and Canal 26; the stated aim was to keep curious visitors away.
The case has been retold many times. Diario UNO's 2019 account lists Marisa Grinstein's 2000 book Mujeres asesinas; a 2006 episode of the Canal 13 series of the same name, with Nacha Guevara as Murano; later adaptations in Colombia and Mexico; a 2016 stage musical, Yiya, el musical, written by Osvaldo Bazán and starring Karina K; and a 2017 Chilean documentary series. The Buenos Aires Herald adds that the musical's songs were by Ale Sergi. In November 2025 the streaming service Flow released Yiya, a five-part miniseries directed by Mariano Hueter and written by Marcos Carnevale, with Julieta Zylberberg as the young Murano and Cristina Banegas as the older woman, La Gaceta and Infobae reported. Her son said he disagreed with how the series portrayed her.
Other victims. Police investigators in 1979 spoke of ten or more possible victims, Infobae reported, but only three cases were brought. In 2026 her son said on a television program that three older women with money ties to his mother had died in what he called mysterious circumstances before the 1979 deaths, El Litoral reported; he gave no names or dates and the claim has not been tested in court. La Capital reported in 2023 that he suspected seven to eleven victims, perhaps more. Diario UNO's 2019 account relays a 2016 report that a married couple to whom she owed money may also have died at her hands. None of these deaths has been charged or proven.
An accomplice. Who supplied the cyanide was never established. Police suspected a third person; her son has suggested a doctor or a biochemist. No one was ever charged.
The poison. Whether it was given in the tea or in the pastries was never settled, Infobae reported. Her son says she told him it was in the tea bags; she said she had killed no one.
The exhumations. Accounts differ on whether cyanide was found in all three women or with certainty only in Mema del Giorgio.
Dates. Formisano's death is dated February 19 by C5N and February 22 (when she was found) by the Noticias Argentinas account. The appeals ruling is dated May 16 or June 28, 1985. Her release is given as 1993, 1995 or 2002, and her death as April 26 or June 23, 2014.
Who went to the police. Most accounts say Mema del Giorgio's daughter went to the police; a 2006 Infobae report said Murano's own son had turned her in. No other report supports that.
1930, May 20: María Bernardina de las Mercedes Bolla Aponte born in Corrientes.
1953: Marries a lawyer and takes the surname Murano.
Late 1970s: Takes money from friends, neighbors and relatives on promises of high interest, signing promissory notes.
1979, February 11: Nilda Adelina Gamba dies after falling ill the day before; a funeral home doctor certifies a natural death.
1979, February 19 or 22: Lelia Elida Formisano de Ayala dies (C5N) or is found dead (Noticias Argentinas); again certified as natural.
1979, March 24: Carmen Zulema del Giorgio de Venturini dies. Her daughter finds the promissory notes missing and goes to the police; exhumations follow.
1979, April 27: Murano arrested by the Federal Police at her home in Monserrat.
1979, June 12: Judge Diego Perés orders preventive detention (C5N).
1980: Found unconscious in Ezeiza prison; a head tumor is removed.
1982, June (June 15 per C5N): Judge Ángel Mercado acquits her for lack of proof; she is freed.
1985, May 16 or June 28: Sala III of the national criminal appeals court sentences her to life for three aggravated homicides by poisoning and fraud; she is briefly sought as a fugitive and gives herself up.
1993 or 1995: Sentence commuted by President Carlos Menem; with the two for one credit she is released (November 20, 1995, per La Gaceta).
1994: Her son publishes Mi madre, Yiya Murano.
1998: Guest of Mirtha Legrand on television (Noticias Argentinas).
2006: Radio 10 interview in which she again denies the killings; Canal 13's Mujeres asesinas dramatizes the case.
2014, April 26 (or June 23): Dies in a care home in Belgrano, Buenos Aires; buried in Chacarita under the name Mercedes Bolla.
2023: Her son auctions her tea set for an animal shelter.
2025, November 13: The miniseries Yiya premieres on Flow.