Smartphones are a rich data trove not only for marketers but also for law enforcement. Police and federal investigators love to get their hands on all that juicy personal information during an investigation. But thanks to the Fourth Amendment of the US Constitution and all the case law built upon it, police generally need a warrant to search your phone—and that includes just looking at the lock screen, a judge has ruled (PDF).
Usually when the topic of a phone search comes up in court, the question has to do with unlocking. Generally, courts have held that law enforcement can compel you to use your body, such as your fingerprint (or your face), to unlock a phone but that they cannot compel you to share knowledge, such as a PIN. In this recent case, however, the FBI did not unlock the phone. Instead, they only looked at the phone's lock screen for evidence.
A man from Washington state was arrested in May 2019 and was indicted on several charges related to robbery and assault. The suspect, Joseph Sam, was using an unspecified Motorola smartphone. When he was arrested, he says, one of the officers present hit the power button to bring up the phone's lock screen. The filing does not say that any officer present attempted to unlock the phone or make the suspect do so at the time.
In February 2020, the FBI also turned the phone on to take a photograph of the phone's lock screen, which displayed the name "Streezy" on it. Sam's lawyer filed a motion arguing that this evidence should not have been sought without a warrant and should therefore be suppressed.
District Judge John Coughenour of the US District Court in Seattle agreed. In his ruling, the judge determined that the police looking at the phone at the time of the arrest and the FBI looking at it again after the fact are two separate issues. Police are allowed to conduct searches without search warrant under special circumstances, Coughenour wrote, and looking at the phone's lock screen may have been permissible as it "took place either incident to a lawful arrest or as part of the police's efforts to inventory the personal effects" of the person arrested. Coughenour was unable to determine how, specifically, the police acted, and he ordered clarification to see if their search of the phone fell withRead More – Source