(This idea popped into my head during a discussion of Trump and Comey, but it is NOT at all about them, this is purely a legal hypothetical.)
Let’s imagine a legal situation in which there is some fact, X, that is either true or false, but we can’t figure out which it is, and are pretty sure we’ll never be able to figure it out.
And there’s some guy, Mr. Smith. And it’s very clear, due to our very contrived situation, that if X is true, then Mr. Smith is guilty of a particular crime. However, if X is false, then Mr. Smith is innocent of that crime, but guilty of an entirely different, unrelated crime.
So, can we prove that Mr. Smith committed the first crime? We can not, because we are unable to determine if X is true. Can we prove that Mr. Smith committed the second crime? We can not, because we are unable to determine if X is true.
BUT… we know with absolute certainty that he did commit one of the two crimes.
Legally, what can we do? Is there a way to put someone on trial for either-crime-A-or-crime-B-but-we-can’t-determine-which?
No, because you have to prove guilt of the offence charged, beyond a reasonable doubt. The way you have constructed your hypothetical, that’s not possible for either charge.
People get charged with multiple crimes pretty routinely, there’s nothing noteworthy about charging someone with multiple crimes, charging someone with A and B and C and D even though you don’t think all four will stick is common practice. There’s also not a problem with making charges that sound contradictory; it’s possible for the state to charge both defendants F and G with murder when it doesn’t know who pulled the trigger. The fact that someone else is being charged for the same crime might provide reasonable doubt, but there’s not a fundamental legal issue with charging both people (and in reality what will probably happen is that one will offer to testify against the other in exchange for a plea deal). Where you run into trouble is If “X” is an element of one crime and “no-X” is an element of the other, and you can’t prove that X or not-X happened beyond a reasonable doubt, then you can’t get a conviction for either crime.
I had heard somewhere that this was the rationale behind necrophilia laws: There were some rape-murder cases where the rape part went unprosecuted because the state couldn’t prove that the victim was alive at the time. But that would make rape and necrophilia an example of a pair of crimes such as the OP describes.
Two people were murdered at the same time inside a locked building, as two different burglars, unbeknownst to each other, stowed away inside the building until after it closed.
After the shots were heard, the police apprehended two suspects inside the building. Both have gunshot residue on their hands. Both have a gun of the same caliber. Unfortunately, the bullets are not recovered in usable condition, so we know that both burglars are murderers, but not who they murdered.
It seems quite difficult to come up with a realistic scenario involving unrelated crimes that are either/or like this. The best I can think up is an extension of the identical twins idea, where you can’t prove which one did it. Suppose identical twins simultaneously murder two different people, in two different locations. There are a dozen witnesses to each crime and forensic DNA, but they escape, and are only later apprehended. So it is absolutely certain that they each murdered someone, but we have no way to prove which twin committed which crime, and (for the sake of the hypothetical) we cannot prove conspiracy beyond a reasonable doubt. Are they acquitted?
The Felony murder rule also helps in cases (for example) where several people commit a robbery together and someone dies, but it is not clear who fired it - (as I understand it) since it’s foreseeable that lives may be lost during an armed robbery, all the parties involved are culpable even though only one (unknown) person among the robbers actually pulled a trigger.
An example that arises in some Commonwealth jurisdictions to deal with this is the relatively rare verdict of “Guilty of A or B but we (ie, the jury) can’t say which”.
It most commonly arises in cases of stealing or receiving stolen goods. Stealing and receiving are mutually exclusive. You can’t logically be both the thief and the receiver. The point gets slightly more complicated if a person is a party to the theft and also has the job of fencing it, but let’s pass over that.
Suppose Fred is found in possession of something very shortly after it was stolen, in circumstances where it is obviously stolen - the sawn off head of Jedediah Springfield, say. Fred admits he was in possession, he admits he knew it was stolen, but will not discuss how he came into possession of it. It is obvious that he either stole it himself, or got it from someone who stole it in such circumstances as to make Fred a receiver.
The law doesn’t really like “gotcha” arguments of the sort that might arise here, despite the entertainment industry’s delight in “loopholes” (see, eg, Double Jeopardy). Fred might try to answer an indictment charging him with stealing by saying “Nyah, Nyah. I received it!” or vice versa. If that is a real prospect, he is likely to be confronted with an indictment charging both stealing and receiving in the alternative, with a jury having the capacity to deliver the hybrid verdict I mentioned above.
If convicted on the hybrid verdict, the maximum penalty is whichever is the lesser of the two alternatives.
Another solution to this sort of problem is to recognise that real facts are rarely as sparse as those in hypotheticals like this. To adapt a common scenario, A and B are in a room where B is killed. Each blames the other. (This is called the “cutthroat defence”.) If the facts just outlined are all we know, then they might both have to be acquitted. But they never are. There is always a wealth of surrounding material about the respective motives of the parties and details about acquisition of the gun so that mostly you can tell who was the shooter even if they don’t admit it, or to indicate that, at the highest the case can be put against either, he was at least a party to the shooting, making him equally culpable. A consequence of the onus and standard of proof is that it is logically quite possible for both to be convicted as parties even if one of them must have pulled the trigger.
Doing research for a professor back in law school, I once ran across a case out of Australia where the defendant was on trial for necrophilia and argued that he reasonably, if incorrectly, believed that the woman was alive but unconscious. The court refused to allow this defense, noting that if true, it constituted an admission that he thought he was committing rape.
(Interesting that Swype knows the word “necrophilia.”)
It’s precisely because of this technical issue that Canada has abolished the offence of receiving and replaced it with possession of stolen goods. A person can be guilty of both theft and possession, so the court is not faced with the “either/or” scenario.
There was the case several decades ago of Colin Thatcher, son of a former premier of Saskatchewan (a province in Canada, just sayin’). His ex-wife was murdered, “bludgeoned to death” in her garage. The case against him was that he either (a) did it himself or (b) hired a hitman, whichever the jury chose to believe. (The trial had some interesting details about how big a screw-up he was, including the time he accidentally neutered the wrong animal, his father’s prize-winning bull.) He was convicted; as one commentator reported it, the charge was “we don’t know exactly what you did but it’s your fault she’s dead”. He continued to make news, such as the time he had one of his horses shipped to the Canadian “Club Fed” he was incarcerated in, so he could go horseback riding.
There are two crimes in Washington, delivering a controlled substance, and delivering a counterfeit controlled substance. If the crime lab lost the evidence, I suppose you could argue the defendant was guilty of one or the other (assuming the other elements were proven). I don’t think the courts would allow a conviction on those facts.
There’s an offense in Canada I heard on the news. The RCMP went undercover into some small town and made a dozen or more arrests for drug sales. One lucky fellow was asked in a bar who sold drugs, and said “gimme $25 and I’ll point you to the dealer.” For that, he also was charged; apparently it’s illegal to ask for a consideration to direct someone to a drug dealer also.
Isn’t that potentially a double jeopardy issue? If I am guilty of theft, then by definition, I have possessed the stolen item, at least for a moment. How can I additionally be charged with possession of a stolen item?