Whenever there is a shooting with a claim of self defense the police will be looking for a reason to arrest you. It's not personal, just their job. They are not there to clear you, they are tnere to make sure there isn't two sides to the story and you made sure only one of you is around to tell it.

Much of it will depend on who you are, who the dead guy is, what you were doing before the shooting, what the dead guy was doing before the shooting, the politics of your local DA, the politics of the people that got nothing better to do than serve on the grand jury, and ultimately the sensibilities of your jury.

You should always expect to at least have your case presented to the grand jury in any shooting.