DC police chief issues order defending citizens' right to record police | The Verge
As long as the photographing or recording takes place in a setting at which the individual has a legal right to be present and does not interfere with a member’s safety, members shall not inform or instruct people that photographing or recording of police officers, police activity or individuals who are the subject of police action (such as a Terry stop or an arrest) is not allowed; requires a permit; or requires the member’s consent.
Additionally, members shall not:
1. Order that person to cease such activity;
2. Demand that person's identification;
3. Demand that the person state a reason why he or she is taking photographs or recording;
4. Detain that person;
5. Intentionally block or obstruct cameras or recording devices; or
6. In any way threaten, intimidate or otherwise discourage an individual from recording members’ enforcement activities.