The Illustrated Guide to Criminal Law Chapter 10: We’ll All Go Down Together Conspiracy pg 32: Limits of Felony Murder
So the question becomes whether the heist was inherently dangerous to begin with, or whether the shooting was foreseeable.
Let’s say nobody but Bahr knew he’d brought a gun along. The plan was to slip in and out without anyone realizing it. All Bahr was supposed to do was alert us so we could escape. The scheme didn’t put anyone in danger, and nobody but Bahr could have foreseen the shooting. In that case, maybe Bahr is liable for the felony murder of the baby, but the rest of us shouldn’t be.
But what if Bahr’s gun was part of the plan?
That’d mean we had anticipated a scenario where he’d have to use it. People who get shot do sometimes die, so we could certainly foresee a situation where someone got killed during the heist. In that case, we’d all be guilty of Felony Murder.