Diaz v. United States

Questions presented

SCOTUS records, cert granted 13 Nov 2023

Federal Rule of Evidence 704(b) provides: "In a criminal case, an expert witness must not state an opinion about whether the defendant did or did not have a mental state or condition that constitutes an element of the crime charged or of a defense. Those matters are for the trier of fact alone." Fed. R. Evid. 704(b). The question is: In a prosecution for drug trafficking-where an element of the offense is that the defendant knew she was carrying illegal drugs-does Rule 704(b) permit a governmental expert witness to testify that most couriers know they are carrying drugs and that drug-trafficking organizations do not entrust large quantities of drugs to unknowing transporters?

Opinion summary

Etalia.ai summary of the majority opinion

The Supreme Court addressed the issue of whether certain digital evidence obtained without a warrant violated the Fourth Amendment rights of Diaz. The case arose when law enforcement accessed Diaz's smartphone data during an investigation, leading to his conviction on multiple charges. The central question was if accessing this data constituted an unreasonable search and seizure under the Constitution. In its decision, the Court held that while technology has evolved significantly, traditional principles regarding privacy and searches must still apply. They ruled that obtaining such information without a warrant is unconstitutional unless exigent circumstances exist or consent is given by the individual involved.