I posted the cites for the applicable law in my post above.
As I said, Michigan's Self Defense Act provides that a person is allowed to use deadly force, without the duty to retreat from any place he or she has the right to be if he or she honestly and reasonably believes there exists imminent death, great bodily harm, or sexual assault to self or others.
People acting in self-defense have a Rebuttable Presumption of Self- Defense which provides substantial immunity from both criminal and civil liability under the laws. When using defensive force against someone, a person is presumed to have held a reasonable fear of imminent death, great bodily harm, or sexual assault, as long as both the following apply:
(a) The individual against whom deadly force or force other than deadly force is used is in the process of breaking and entering a dwelling or business premises or committing home invasion or has broken and entered a dwelling or business premises or committed home invasion and is still present in the dwelling or business premises, or is unlawfully attempting to remove another individual from a dwelling, business premises, or occupied vehicle against his or her will.
(b) The individual using deadly force or force other than deadly force honestly and reasonably believes that the individual is engaging in conduct I described above
This legal presumption must be overcome by the prosecutor, who is required to present evidence at each stage of the criminal proceedings, to rebut the presumption that the person did not act within provisions of the Self-Defense Act. Only if the prosecutor has presented enough evidence to rebut the presumption of self defense will the individual using deadly, or less than deadly force, be subject to criminal prosecution.
There are exceptions to the presumption created by the Self Defense Act cited above.
Specifically:
The person against whom force is used has a legal right to be present in the dwelling or vehicle (such as an owner, lessee or titleholder);
the person being removed is a child or grandchild or in lawful custody of the person against whom the defensive force was used;
the person against whom defensive force is used is a police officer engaged in performing official duties; or
the person using defensive force was engaged in an unlawful activity or using the dwelling or vehicle to further an unlawful activity.
If none of these specific exceptions apply, then the person is immune from criminal prosecution.
In addition to immunity from criminal penalties, an individual using force in self-defense or defense of another in accordance with the Act would not be civilly liable for damages caused to the person against whom the force was used nor to anyone else claiming civil damages stemming from the incident. Additionally, the court is required to award actual attorney fees and costs to an individual sued for civil damages if that person is deemed immune from civil liability under the Act.
How far a particular prosecutor tends to pursue charges against a person using force in self-defense or defense of another varies quite a bit. My county prosecutor tends to not pursue charges against a person using force, even if there is some aspect that seems to be questionable in terms of complying with the act. I, however, live in Kent County. I've been made aware of a persecutor who will pursue charges and then apparently drop them after a very lengthy investigation. Those in Michigan know to whom I referring.