Oops. The above was actually meant for the current "Conjoined Twin on Jeopardy* thread.
I see what you did there- my kids have watched “Labyrinth” at least 4 times this summer already. 
As for the above-mentioned case of death during a gun crime- if during, say, an armed robbery, one of the people in the bank/convenience store/whatever has a heart attack during the execution of the crime and then dies, then all the bad guys can also get a murder charge added to the list of bad things they did that day.
Plus, the twin who did not commit the murder would not be committing perjury, assuming he answered “no” to the question of “did you kill the victim?”
I wager 20 quatloos on the tall one.
Would this discussion also apply to human centipedes?
If it’s half of your body, one could argue that you’re an accessory to murder, being that you aided in said murder.