Suicidal Cases Involving Sodium Nitrite: Focus on Crime Scene and Investigation

Suicidal cases involving sodium nitrite have been reported worldwide. However, postmortem features, such as brownish or grayish livor mortis, remain difficult to interpret, especially as decomposition advances. Here, we present three fatal cases (2020-2023) presumably caused by sodium nitrite ingestion. In these cases, characteristic nitrite-induced changes were inconsistent or obscured by decomposition, but ingestion traces (cup or bottle near the decedents) were observed at each scene. Additionally, containers labeled “sodium nitrite” were found in two cases; however, since sodium nitrite is designated a suicide-hazardous material in South Korea, future scenes may rarely reveal such clear labeling. Although autopsy, including methemoglobin testing, can confirm the cause of death, any delay in the investigative process risks the loss of critical evidence about the ingestion process and other factors. This underscores the importance of focusing on early scene evidence, particularly ingestion traces, and conducting thorough chemical and forensic examinations. Our findings illustrate that timely detection of ingestion-related evidence and subsequent forensic analysis, in conjunction with autopsy results, can elucidate a decedent’s cause and manner of death and clarify any criminal implications.