Howdy.
I am not a lawyer, so take my comments with a grain of salt, do your own legal investigative work, and hire a lawyer to give you legal advice.
This is an excerpt from the CCDW Instructor handbook I found in a quick search, that basically says what I was taught.
KRS 503.085 does not set forth a justification defense. However, it does affect your rights in the event you use deadly force and claim a justification defense. Subsection(1) A person who uses force as permitted in KRS 503.050, 503.055, 503.070, and 503.080 is justified in using such force and is immune from criminal prosecutionand civil action for the use of such force, unless the person against whom theforce was used is a peace officer . . . who was acting in the performance of his orher official duties and the officer identified himself or herself . . ., or the personusing force knew or reasonably should have known that the person was a peaceofficer. As used in this subsection, the term “criminal prosecution” includes arresting, detaining in custody, and charging or prosecuting the defendant. This language provides that if you have used deadly physical force and are found to have a justification defense under KRS 503.050, 503.055, 503.070, and 503.080, you cannot be criminally prosecuted nor civilly sued. However, you would not be immune from prosecution if the person you used force against was either known to you or should have been known to you as a peace officer. Prosecution includes arresting, detaining in custody, and charging or prosecuting the actor. However, just because you claim you are justified does not automatically mean you cannot be prosecuted.
Let’s look at subsection(2), A law enforcement agency may use standard procedures for investigating the use of force as described in subsection (1) of this section, but the agency may not arrest the person for using force unless it determines that there is probable cause that the force that was used was unlawful. If you have used deadly physical force against another person and are claiming a justification defense under KRS Chapter 503, law enforcement officers will still investigate the case. If you tell them that you acted pursuant to one of the justification defenses in Chapter 503, they will investigate and determine if it is more likely than not true that your defense will hold up in court. If they believe it is more likely than not true that it will succeed, they will not arrest you. That does not mean they will not investigate the case further. If they develop enough evidence to indicate guilt, the case may get referred to a grand jury. If you are indicted, you will be prosecuted for the offense charged. If the court finds that your defense is justified, you will be acquitted, but if not, you will be convicted of the offense and punished.