Coronavirus disease 2019 (COVID-19) is a manifestation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and its major symptoms include pulmonary complications, such as pneumonia. However, it also involves the cardiovascular system and the developed myocarditis can lead to sudden unexpected death. Herein, we present a case in which a patient died four days after release from isolation due to SARS-CoV-2 infection. SARS-CoV-2 was confirmed again during postmortem (PM) inspection at the scene of death. Autopsy revealed myocarditis and evidence of pulmonary involvement with SARS-CoV-2. Pathological examination revealed myocardial perivascular infiltration of lymphocytes and macrophages with multifocally injured cardiomyocytes. The pathological findings of COVID-19–induced myocarditis differ from those of other viral myocarditis, and we assume that different pathophysiological mechanisms could have been responsible for this manifestation. After a comprehensive PM examination, including gross dissection, microscopic examination, PM computed tomography, and PM laboratory tests, the cause and manner of death were determined to be myocarditis caused by COVID-19 and naturally, respectively. This case highlights the significance of autopsy and comprehensive PM examinations in both forensic and public healthcare systems.