Forensic Science: Evidence Collection Protocols and Precedent Cases

Several important Supreme Court cases have established crucial rules for the collection of forensic evidence from crime scenes.

Summary: This case involved a drug bust gone wrong, resulting in the death of an undercover police officer and injuries to others, including the suspect, in the suspect's apartment.
Initial Investigation: Following a brief search by responding officers, homicide detectives took over, spending $4$ days conducting an extensive search. They opened drawers, ripped up carpet, and seized between $200$ and $300$ pieces of evidence from the apartment without a warrant.
Conviction and Appeal: This evidence led to Mincy's conviction for homicide and narcotics charges.
Supreme Court Ruling: The U.S. Supreme Court ruled the evidence inadmissible because it was not obtained properly; no warrant had been issued.
- Emergency vs. Prolonged Search: While an emergency initially allowed for a quick, warrantless search, this emergency could not reasonably justify a $4$ -day extensive search, especially as the detailed search only began after all the dead and wounded had been removed.
- Warrant Requirement: The police should have obtained a warrant after the immediate emergency subsided to continue their search, as a warrantless search based on an emergency is limited in its duration.
- Scene Control: Importantly, the police do not have to relinquish control of a crime scene while seeking a search warrant; they can close and restrict access until searching can legally resume.

Summary: This case involved a fire at a furniture store. The fire department extinguished the blaze before midnight. An investigation by fire and police officials began at $2$ A.M. but was halted at $4$ A.M. due to darkness, heat, and steam.
Subsequent Entries: Over the next three weeks, investigators repeatedly returned to the scene to collect and remove evidence for a possible arson investigation, again without warrants for later entries.
Conviction and Appeal: Tyler was ultimately convicted of arson, but the Supreme Court ruled the evidence inadmissible.
Rulings on Fire Investigations:
- Initial Entry: Entry to fight a fire requires no warrant.
- Reasonable Time: Once inside, officials may remain for a reasonable time to investigate the cause of the blaze.
- Subsequent Entries: Additional entries to investigate the cause of the fire thereafter must be made pursuant to warrant procedures.
Additional Problem: A major issue was that the crime scene was not controlled by the police and was left abandoned between searches, creating opportunities for evidence to be added, removed, or tampered with, which relates to the