You have the right to record as long as you are not disrupting their activities. No one can search or delete evidence on your phone without your consent or a warrant.
Offer to take a few steps back if the situation escalates.
As a participant in a public event, you have the right to photograph and take videos of law enforcement officers, but often documentation is taken, destroyed, or obstructed by law enforcement. We recommend you to stay calm, point out that you are not disrupting anyone else's activity, that you have the right to record public/law enforcement activities, and that they cannot expect privacy on public properties. It is within your rights to record evidence. You can offer to take a few steps back from the scene to not disrupt their activities.
If you are arrested for reporting on an event as either a credentialed or non-credentialed journalist, you may be allowed even more protections and avenues of legal recourse. Professional journalists—as well as bloggers and livestreamers—have the right to document police activity at protests and demonstrations without undue state interference under the First Amendment right to freedom of the press. If they ask for your phone or request a phone search, you can ask for a warrant and verbally state that you do not consent to the phone search.
Videos from the Reyets app are backed up and accessible on the cloud, in case your original recording is destroyed by law enforcement.