Actually, the Michigan Prosecuting Attoerneys Coordinating Council -- an autonimous state agency within the Michigan Department of Attorney General -- provides this advisory definition, with brief remarks to the state’s prosecutors regarding self defense. It is based on the law as it now stands and has been well established in MIchigan:
“a legally-justified use of force to protect one's self, another person, or property against some injury attempted by another person ... the right to repel force with force ... the defendant (i) must have honestly and reasonably believed that he had to use force for protection, (ii) may use only the type and degree of force that seems necessary for protection at the time based on the circumstances known to him, (iii) must not have acted wrongfully and brought on the assault (i.e., provoked the attack) ... In Michigan, a Prosecutor has the burden of disproving a defendant's self-defense claim beyond a reasonable doubt.”
Please take special note of the last sentence, repeated here for emphasis:
“In Michigan, a Prosecutor has the burden of disproving a defendant's self-defense claim beyond a reasonable doubt.”
While this certainly allows for real investigation to uncover all pertinent facts when self defense is claimed, it also places a very heavy burden of proof on the prosecutor who would bring charges. It explains why we see virtually no charges brought or prosecutions pursued in cases of legitimate self defense. (Not all claims of self defense are legitimate, by a long shot, as court records clearly show.)