Criminal investigations have changed drastically in the last 30 years. The rise of cell phones and smartphones has created a new field of evidentiary law related to these electronic devices. Cell phone providers can track the location and behaviors of their customers, and police often seek this information to place suspects at crime scenes. However, both cell phone companies and their customers have a Fourth Amendment right against unlawful search and seizure of their phones or data. Therefore, law enforcement must obtain a valid warrant and demonstrate probable cause that evidence of a crime will be found before they can compel a cell phone company to turn over the data. The Massachusetts Court of Appeal recently reversed a lower court’s ruling that had suppressed some evidence of assault crimes that was obtained with a warrant from the defendant’s cellular phone provider.
According to the facts discussed in the appellate opinion, the defendant had been suspected of a chain of assaults over the course of about two weeks, based on a tentative identification by one of the crime victims. After another victim notified police that they saw their assailant in public, the police apprehended and questioned the defendant. Based on other evidence, the police sought a search warrant for the data related to two phone numbers associated with the defendant. Although the warrants were issued, the defendant’s counsel successfully challenged the warrants and the evidence would not be admitted, but for the State’s appeal.
On appeal, the Court discussed the requirements for a valid search warrant for cell phone data to be issued. Law enforcement must establish probable cause that the suspect committed a crime, that the suspect’s location data would be helpful in solving or proving the crime, and that the suspect had a cell phone at the relevant times. This requires demonstrating the suspect’s association with the cell phone and showing that location data from the phone is relevant to the investigation.