States have wide variance in what their felony murder laws require. Some say that the death must have been foreseeable or committed “in furtherance of” the crime. In a robbery using guns, for example, objective people would most likely agree that death was a foreseeable outcome.
Federal law lists 11 crimes that can serve as a basis for felony murder: arson, escape, murder, kidnapping, treason, espionage, sabotage, aggravated sexual abuse or sexual abuse, child abuse, burglary, or robbery.
Legal experts say the one most likely to apply in the Capitol riot is burglary, defined as entering a building with the intent to commit an additional crime. Simply having entered the Capitol unlawfully would not be enough, and intent is difficult to prove.
Beyond that, there are other significant hurdles, said Guyora Binder, an expert on felony murder at the University at Buffalo School of Law. One is the question of who qualifies as an accomplice.
“Let’s say you enter with the intent to commit one crime, and half an hour later I enter with the intent to commit another crime and we never see each other, and I’ve never heard of you,” he said. “So we’re both committing burglaries, but we’re not committing the same burglary. I’m not your accomplice. You’re not my accomplice.”
Another wrinkle: Whether the death must be foreseeable or in furtherance of the underlying felony is “an open question” in federal law, Mr. Binder said, because courts have ruled different ways.
Still another question is raised by the deaths of Ms. Babbitt and Rosanne Boyland, who appears to have been trampled to death as fellow rioters fought their way into the building. A fourth person died after a stroke, and a fifth after a heart attack.