For these types of questions, I find it helpful to go to the statutory definitions of the crime in the relevant jurisdiction. I’ll pick New York (because that’s the law I’m most familiar with, though I should warn you that I know little of criminal law beyond what I learned in my first year of law school). New York’s Penal Law defines the homicide crimes in Article 125.
Second degree (non-capital) murder is defined, in relevant part as: "With intent to cause the death of another person, he causes the death of such person or of a third person. Could you be prosecuted under this statute? Well, assuming the burglar (or anyone else) dies from the drain cleaner, we’ve “cause[d] the death of such person or a third person.” The one question would be if you can be shown to have an intent to cause death.
Intent can sometimes be difficult to prove. If you (while conscious and sane) point a gun at someone and pull the trigger, it is pretty clear that you intentionally shot the person, but laying out the baggies of drain cleaner is more ambiguous. However, if the police and prosecution could find evidence that you set out the drain cleaner with intent to kill the burglars (like, for instance, you bragged about your scheme to your buddies), it seems prettly likely that you could be convicted of intentional murder.
Next on the homicide hit parade is First Degree (intentional or voluntary) Manslaughter, which is defined, in relevant part, as: “With intent to cause serious physical injury to another person, he causes the death of such person or of a third person.” This could be proven if you showed you intended to seriously injure (but not kill) the burglars, but they died anyway.
Second Degree (reckless or involuntary) Manslaughter is defined, in relevant part as: “He recklessly causes the death of another person.” The question here is what is recklessness. Penal Law section 15.05 defines recklessness as:
- “Recklessly.” A person acts recklessly with respect to a result or to a circumstance described by a statute defining an offense when he is aware of and consciously disregards a substantial and unjustifiable risk that such result will occur or that such circumstance exists. The risk must be of such nature and degree that disregard thereof constitutes a gross deviation from the standard of conduct that a reasonable person would observe in the situation. A person who creates such a risk but is unaware thereof solely by reason of voluntary intoxication also acts recklessly with respect thereto.The key to recklessness is that you knew of a “substantial and unjustifiable risk” and disregarded that risk. Even if you didn’t intend to cause death or injury, it seems clear from the hypothetical that by placing the unmarked drain cleaner where the burglars would likely find it shows knowledge of the risk of them finding and using, and a disregard of the risk that they could die thereby. As such, there’s a good chance that you could be conviced of reckless manslaughter.
The lowest rung on the homicide ladder is criminally negligent homicide, defined in relevant part as: " with criminal negligence, he causes the death of another person." Criminal negligence is defined as: “A person acts with criminal negligence with respect to a result or to a circumstance described by a statute defining an offense when he fails to perceive a substantial and unjustifiable risk that such result will occur or that such circumstance exists. The risk must be of such nature and degree that the failure to perceive it constitutes a gross deviation from the standard of care that a reasonable person would observe in the situation.” If they can’t get you on recklessness, they may well get a conviction on the basis that leaving unmarked baggies of drain cleaner disguised as drugs lying about is criminal negligence.
So, whether or not you did the world a favor by setting the cokeheads up for their demise, there’s a good chance that you could be convicted of one of the levels of homicide. Which one would depend on the discretionary charging decision of the local prosecutor and the particular culpable mental state (intent to kill, intent to injure, recklessness or criminal negligence) the prosecution could demonstrate to the jury.