People seem to be a little confused about what "Miranda" means. You do not have "Miranda Rights". "Miranda" is a "warning". A procedural issue. Also, you do not have a "right" to be given a "Miranda Warning". The Miranda Warning covers your 5th and 6th Amendment rights (and technically, 14th, probably). There is no need for police to advise you that you are under arrest and of what your 5th and 6th Amendment rights are, to allow a statement to be admissible, unless you are in custody AND they are asking questions of you, the answers to which they want to use against you in the future.
So when you shoot someone in a justified shooting, if you tell the responding officers NOTHING, as Badge130 points out, you will very likely be arrested and taken to the station and booked if there is probable cause to believe a crime was committed and you committed it. "Probable Cause" does NOT mean a "certainty" or "beyond a reasonable doubt". THEN you can call a lawyer, hours later.
So if you're at your house and the police get there and they find you there and a dead guy laying on the floor with half his head gone and you say nothing, invoking your 5th amendment right against self-incrimination, they are going to first secure you in handcuffs. They are then going to look for other suspects in your house to make sure it is safe. Then they're going to secure any weapons they find. Then they're going to get a search warrant and search EVERYTHING in your house looking for identification, guns, ammunition, anything to suggest a motive, identity of the dead guy, etc. In other words, if your wife has any toys in the nightstand or if you have any embarrassing items at all, they're going to find them and probably make jokes about them, cops being cops..... And it's all going to be on video most likely. God help you if you have any questionable stuff, like a little bit of weed or an unregistered pistol and they find it. You'll be charged with it after a perfectly justified shooting.
On the other hand, if you were involved in a shooting at a liquor store and you invoke your 5th amendment rights immediately and say NOTHING, and the store owner or any witnesses are still alive, they're going to tell the cops: "That guy came in behind me, then someone else came in and announced a holdup and pointed a gun at the clerk. That guy produced a gun from somewhere and shot the bad guy in the back of the head."
Now the police likely do not have probable cause to believe a crime had been committed as far as you shooting the guy, and that you committed it. They will likely detain you and try to determine your identity and then let you go from the scene. Or they MAY let you call your lawyer from the scene so he can tell you: "Just give the cops your name and they'll let you go. That will be $1200.00 please." If, for whatever reason you're STILL not talking weeks afterwards, they can always (in Michigan anyway), get an investigative subpoena from a judge and COMPEL you to talk to the prosecutor, under oath. Or if the bad guy isn't dead, they could get an order from a judge to hold you in custody as a "material witness" until your testimony is no longer needed.
