http://www.hawaiinewsnow.com/story/32485087/honolulu-cop-under-investigation-after-threatening-facebook-post-about-black-lives-matter

HONOLULU (HawaiiNewsNow) -
A Honolulu police officer is under investigation for a Facebook post that appears to threaten Black Lives Matter members.
In the post, officer Vincent Tripi writes, "(expletive) BlackLivesMatter. Unfriend me PLEASE if you’re offended. I’m locked and loaded 24/7. Come!”

HPD is paid extra money to be moral and professional 24/7, so he violated that.  Also any employee, government or commercial, can be administratively punished for their speech.

On the other hand some people view BLM as a criminal and racist organization...

The police are public entities that we are supposed to look up to and respect (if they earn/deserve it). Because of this we hold them to a higher standard. They should live up to that standard.

http://www.hawaiinewsnow.com/story/32485087/honolulu-cop-under-investigation-after-threatening-facebook-post-about-black-lives-matter

HONOLULU (HawaiiNewsNow) -
A Honolulu police officer is under investigation for a Facebook post that appears to threaten Black Lives Matter members.
In the post, officer Vincent Tripi writes, "(expletive) BlackLivesMatter. Unfriend me PLEASE if you’re offended. I’m locked and loaded 24/7. Come!”

I think its stupid that he got in trouble for a truthful post.  BLM is horrible and police should have a right to voice that.  No matter what job you have anything you post in private time should be protected free speach.  Hey after all look at all these people supporting the horrible BLM "movement".  Even obama supports them.

Do Police have free speech rights off duty?

Good question.
I have to say yes. It's in the constitution.

His problem is that he associated his job with his personal views.

Not commenting on Tripi here, but police officers have similar rights as anyone else while off duty.  However when they speak in a manner that is on behalf, or suggests being on behalf of their employer then that can be an issue.  Also there are professional standards that go into how one conducts themselves in their personal lives.  The HPD also has also implemented a pretty encompassing social media policy.

Despite the above and no matter how anyone feels on the topic, right, wrong or indifferent, the posts in no way stood to be a benefit to anyone including the author and could only produce negative results.  Not a wise decision. 

Simple answer is yes they do,

That being said you do not have a constitutional right to employment and if what you do or say effects your employer they have every right to take action against you.

Simple answer is yes they do,

That being said you do not have a constitutional right to employment and if what you do or say effects your employer they have every right to take action against you.

Unless there's a union involved.  Then it's between the employer and the union!   

Do Police have free speech rights off duty?

Good question.
I have to say yes. It's in the constitution.

His problem is that he associated his job with his personal views.

I was thinking the same thing.

I was thinking that if he had not posted any photos in uniform and had not stated his profession he might be immune. But as soon as someone does something private in a work uniform they run the risk of people thinking they are speaking for their employer.

On an off topic sort of, I want to see what would happen if I wore a union shirt to a politician's rally when the union endorsed someone else.