Cellphones are often involved in criminal investigations. The authorities may be looking for a wide variety of different types of evidence. They may want to read a person’s text messages, for example, or look at their browser history. In most cases, the police are required to get a search warrant if they want to search someone’s device without their consent.
In the same way that you can refuse to give consent to a search of your home, you are not obligated to allow the police to unlock your phone. For them to do so, they have to get a search warrant from a judge.
That said, there is something known as the third-party doctrine that can impact how the police are able to obtain certain information. Essentially, when you voluntarily share information with a third party, it reduces your expectation of privacy.
Your location data
An example of this is that many apps ask to track your location data. You may approve them, giving the app permission to use your phone to determine your location at any given time.
Once you do this, you do not have the same expectation of privacy as if you didn’t opt to share your location. The police may be able to approach the appropriate third party and get your location data from them. In this sense, the police may not need to unlock your cellphone. They can still get the information that they need, which may then be used as evidence against you if your location data places you near the scene of the crime.
If you are facing serious charges, it is important to understand what restrictions the police have when gathering evidence and what legal defense options you have.
