Massachusetts police, like police everywhere, don't like being filmed. Police in America, and I am sure throughout the world, have a history of illegally arresting people for filming, and taking cameras.
The difference between Massachusetts and the rest of the U.S., with the possible exception of Illinois, is that Massachusetts state law on wiretapping makes it a criminal offense to record audio of another person, even in public, without the other person's knowledge of consent.
Before, police were arresting anyone (at least anyone who wasn't a big television or radio station with lawyers on retainer) who openly recorded them. The courts stated to them they were clearly breaking the law and to knock it off. But, unfortunately, the courts did not rule that secretly recording isn't a First Amendment right. Though it should be.
Police are government servants, and unlike the janitor hired to clean a school, they have arrest powers. They have the power to detain someone up to about 48 hours before the person can see a judge. In a way they are demi-gods over our lives, demi-gods with almost no accountability.
Karen Dziewit was creating a disturbance in Salem, Massachusetts. She was drunk and disorderly and screaming at the tenants of a building one night, recently.
The police had probable cause for an arrest, unquestionably. Dziewit at one point hit play on the record function of her phone, recording herself and the police. The police after bring her to the station, later found out.
So Dziewit is being charged with illegal wiretapping. Though she shouldn't be. An interaction with a public official is a protected First Amendment activity. Police themselves, record interactions with their dashcams, and almost never inform the public when they do so.
Also, taking into consideration that police often illegally arrest, erase and violate the free speech and press rights of people only recorded, the right to secretly record should be protected to help keep officials honest. Like the saying that with concealed guns, criminals don't know what person is carrying, so they must be wary of robbing anyone, with concealed cameras, bad cops should be wary of violating the rights of anyone.
Indeed, prosecutors and internal affairs units should do operations where they pose as ordinary citizens, recording police. Cops who abuse their authority and illegally erase and arrest the person recording, should be fired immediately. That probably won't happen, though.
Lastly, the police searched this phone afterwards. There is a coming Supreme Court decision on do the police have the ability to search a phone without a warrant, after any arrest. If you are arrested for an unpaid parking ticket, should the government look into everything have stored on your phone? I don't think so. There is no weapon in your phone, just data that the police want to get their hands on.
Maybe it information about political groups you belong to or your political activism. The government should not have access to it without a warrant, the Fourth Amendment agrees with me.