Why yes, you can video police

From this article: U.S. Department of Justice Slaps Baltimore Police Over Right to Record Issue

"On Monday, the Department of Justice slapped the Baltimore Police Department with another letter, condemning it for writing such a vague general order and for allowing the harassment to continue.

"It is a very impressive read. Eleven pages of case citations and Constitutional clarifications. One of the most solid efforts from the federal government in protecting the rights of citizens to record police."

From the Letter from the U.S. Attorney General comes these tidbits, as quoted in the article above:

No individual is required to display 'press credentials' in order to exercise his/her right to observe, photograph, or video record police activity taking place in an area accessible to, or within view of, the general public.

And this:

In addition, policies should prohibit more subtle actions that may nonetheless infringe upon individuals’ First Amendment rights. Officers should be advised not to threaten, intimidate, or otherwise discourage an individual from recording police officer enforcement activities or intentionally block or obstruct cameras or recording devices.

The millstones of the gods grind slowly
but they grind exceeding fine.