Can the police take my cell phone if they are investigating a crime?
Unless an officer has a warrant, they may not take your property. That includes your cell phone. Now, if you are placed under arrest and your cell phone is in your possession when you’re placed under arrest, your cell phone will be put into the police evidence room or at the very least, held at the jail in property. At that point, the law enforcement can go and get a warrant and search your phone.
The prosecutor’s office can request that your phone be searched and they can get a judge to sign a warrant permitting them access to your cell phone. They can’t do that unless they’re able to connect your cell phone to an offense.
For instance, if you’re arrested for a DUI, they have no reason to look at your cell phone. However, if you are arrested for a crime and they believe that you may have texted in order to communicate about that crime, posted things on social media, have photographs or video, they’re going to ask for a warrant and they’re going to open up your cell phone.