The Murder of Diogo Gonçalves

The disappearance and investigation

Diogo Gonçalves was 21 when he was killed in the Algarve in March 2020. Investigators linked Maria Alexandra Malveiro Davidachwili and Mariana Guerreiro Fonseca to the case after parts of Diogo's remains were found in separate locations in the Algarve and his vehicle was located near one of the recovery areas.

Police and prosecutors also examined financial activity connected to approximately €70,000 that Diogo had received as compensation following his mother's death. At trial, the prosecution argued that obtaining that money was central to the events surrounding the crime.

Conflicting accounts

The defendants gave changing and conflicting versions of what happened. Those accounts were not treated by the court as interchangeable facts. The first-instance court in Portimão ultimately concluded that Maria Malveiro was the person who killed Diogo. It did not, at that stage, find sufficient proof that Mariana Fonseca participated in the homicide itself.

That distinction is important because the legal position later changed on appeal. Crime by Region therefore separates the first-instance outcome from the later final appellate result instead of presenting the earliest judgment as the last word.

The 2021 first-instance judgment

On April 27, 2021, the Portimão court convicted Maria Malveiro of qualified homicide and several additional offences, imposing an aggregate sentence of 25 years, Portugal's maximum prison term.

Mariana Fonseca was initially acquitted of homicide but convicted of other offences connected to the aftermath and financial conduct. She received an aggregate four-year sentence and was released while the judgment was subject to further proceedings.

Appeal changes the result

The Public Prosecutor appealed the homicide acquittal concerning Fonseca. Portugal's appellate courts later reversed that part of the first-instance judgment and convicted her for homicide in co-authorship. Reporting on the final appellate history states that the Supreme Court of Justice maintained her homicide conviction but reduced the aggregate sentence to 23 years in prison.

Maria Malveiro died in custody in December 2021. Her death did not alter the judgment already entered against her.

Fonseca's flight and 2026 arrest

After a warrant was issued for Fonseca to serve the final prison sentence, Portuguese authorities were unable to locate her in the country. The Polícia Judiciária coordinated with Interpol and foreign counterparts in an effort to find her.

On March 5, 2026, Mariana Guerreiro Fonseca was detained in Jakarta, Indonesia. The Polícia Judiciária publicly confirmed the arrest the next day and said legal procedures were underway to extradite her to Portugal so that she could serve the 23-year sentence.

Current status

The homicide is judicially adjudicated. Maria Malveiro was convicted at first instance and received 25 years; Mariana Fonseca's initial homicide acquittal was later reversed, and the Supreme Court ultimately left her with a 23-year effective prison sentence. As of the March 2026 official update, Fonseca had been arrested in Indonesia and extradition procedures were underway.

The page does not treat any one defendant's changing account as independently established fact. It relies on the judgments and the later official account of the final conviction and international arrest.