The dispute expanded beyond civil property rights in early 2024 when Gabriel filed a formal petition with the São Paulo Court of Justice requesting the exhumation of his mother's remains. Gal Costa’s official death certificate listed myocardial infarction and complications from a head and neck cancer procedure as causes of death. No autopsy was performed at the time of her passing, a decision made by Petrillo that surprised Costa's close friends and colleagues.
Gabriel’s court filing questioned why no post-mortem medical examination occurred, citing sudden changes in her health and contradictions surrounding her final hours. He also petitioned for her remains to be transferred from the São Paulo crypt purchased by Petrillo to the São João Batista cemetery in Rio de Janeiro. Costa had purchased a plot there years earlier to be buried alongside her mother, Mariah Costa Penna.
São Paulo judges denied the exhumation request on procedural grounds, ruling that criminal investigations into potential foul play fall under police purview rather than probate court oversight, and noting that the initial medical filings showed no prima facie evidence of a violent crime. Gabriel's attorneys subsequently pursued administrative pathways to execute Costa's documented wish to rest beside her mother in Rio.
