A masked guy breaks down your door w/o an Article III warrant absent exigent circumstances? Yeah, I’d agree. Trick will be that pressing the murder charge would be federal since a federal agent dies in the line of official work (though illegal), which would give the president grounds to push for death.
Which should be easy enough - just dress as they do - do we have any latent serial killers around? Because this would be a nice chance for them to start racking up kills. Dress up as ICE, kill some ICE goons, then calmly walk away because not even other ICE can tell you aren’t one of them. Some folks might blow whistles and boo you, that’s about the end of the consequences. If you turn up on security footage - well, no, you really didn’t. ICE did.