Ricardo Barreda

Ricardo Alberto Barreda (16 June 1936 – 25 May 2020) was an Argentine convicted mass murderer and former dentist. He was born in La Plata, Argentina. On November 15 1992, he murdered his wife, two daughters and his mother-in-law. In 1995, he was sentenced to life imprisonment. He was granted house arrest in 2011, but was soon put back in jail after violating it. 
Barreda died of cardiopulmonary arrest caused by Alzheimer's disease on 25 May 2020 in Buenos Aires, aged 83.