Why could vomit be significant at a crime scene?

Vomit at a crime scene can provide critical forensic evidence, particularly concerning the presence of substances such as drugs or alcohol. When investigators analyze vomit, they may find residuals that could indicate ingestion of various substances prior to a crime event. Testing the contents can reveal not just illicit drugs but also prescription medications, which can help to establish behavior or intent before the incident.

Additionally, identifying drugs in vomit can point towards someone’s state of mind or condition at the time of the crime, which could be instrumental in constructing a timeline or understanding the victim's actions leading up to the event. Thus, the evidence found in vomit can play a key role in the investigation by providing insights into substance use that might be relevant to the circumstances surrounding the crime.