Guilt of a character in a convoluted murder from a whodunnit movie

Question

In a movie I recently watched, a rather convoluted murder took place. As a matter of fact, it was so convoluted that I have no idea if the character was guilty or not. I'll try my best to keep the details vague so as not to provide spoilers.

Person A is a medical professional, caring for person B. In A's medical bag there are two different flasks of pills; one that helps treat B's condition and one that would kill B. After administering the pill, A takes a look at the label on the flask and notices that he accidentally gave B the lethal pill, not the beneficial pill. Apparently, B is not very concerned with his own death, and moreover believes that A made a honest mistake and is fond of A. Hence, B comes up with a plot to make his death look like suicide and A reluctantly agrees to participate. The plot involves B commiting suicide, and A going through a number of deceptions in order to secure an alibi, but nothing else that would normally be illegal (at least with B's permission). The plan is put into motion, and B indeed dies by his own hand.

The big twist is that the main villain has, unbeknownst to A and B, mislabelled the two flasks with the intention of killing B. The pill that A gave B would not have caused any bad effects, and B would have lived if the cover-up plan was not executed.

Clearly, the villain is guilty. But what about A? Has he committed any crimes? Is he guilty of accidenatally causing B's death? Or possibly obstruction of justice?

Answer 1

The death was made to look like a suicide - but the death actually was suicide, as it turns out. The alibi given to police was, presumably, technically true (person A likely was out of town at the time of death.) Although there was intent to mislead the officer, what misleading was actually done?

The Wisconsin law for obstructing an officer says:

(1)  Except as provided in subs. (2m) and (2r), whoever knowingly resists or obstructs an officer while such officer is doing any act in an official capacity and with lawful authority is guilty of a Class A misdemeanor. (2) In this section:
(a) “Obstructs" includes without limitation knowingly giving false information to the officer or knowingly placing physical evidence with intent to mislead the officer in the performance of his or her duty...

It's unclear whether what they did meets this criteria, especially if person A is careful to limit his statements to police to the truth (or exercises his right to remain silent.) I suppose the dead body itself might be the physical evidence placed with intent to mislead the officer, although that seems shaky. In any case, person B was the one who placed the body, not person A, and you obviously can't prosecute person B.

But if placing the body does count, it appears that person A might still be guilty of conspiracy to obstruct, even if he didn't do that part:

...whoever, with intent that a crime be committed, agrees or combines with another for the purpose of committing that crime may, if one or more of the parties to the conspiracy does an act to effect its object, be fined or imprisoned or both not to exceed the maximum provided for the completed crime; except that for a conspiracy to commit a crime for which the penalty is life imprisonment, the actor is guilty of a Class B felony.

Certainly, they agreed to mislead the police (whether they ultimately did or not), and specific acts to accomplish that goal were done by the parties. So, I believe that person A might be guilty of conspiracy to obstruct.