Theological Error in the First Degree

I don't understand.

A 28-year-old mother reportedly murdered two of her children and severely injured two others, in what was an apparent attempt at an exorcism. Zakieya Avery and another woman who is 21 years old were reportedly attempting to release demonic spirits they thought had possessed the siblings, reports the Washington Post.  They were each charged with two counts of first-degree murder and two counts of attempted first-degree murder.
Police: Maryland Mom Kills Two of Her Toddlers In Exorcism Attempt

Given the wording of Maryland's murder in the first degree statute, I don't see how this case fits the description, unless an amateur performing an exorcism counts as “Mayhem.”

“This was all about what was in their minds,” said Capt. Marcus Jones, commander of the Montgomery County’s major crimes unit. “They felt like there was something bad going on with the children, and they were trying to release it.”

So... not even the police think that the two women had set out to kill the children? But isn't that a requirement for a first-degree murder charge unless felony murder is being alleged? This seems kind of like a prosecutor going after low-hanging fruit by playing the “mother kills children - she must be a bad person” angle. Now, as far as I'm concerned, this is what happens when you start believing in supernatural forces that you can't see, but can affect the mundane world and everyday people, and can, in turn be affected by them. It's not like the idea of supernatural possession is at all new idea. And plenty of people will tell you that even lay believers can cast out demons. About three seconds with Google is all you need. (And, sadly, this isn't the first time that an exorcism has ended badly and lead to criminal charges.)

As much as we hear about a secular-lead "War on Christianity," why isn't something like this a part of it? Think that there shouldn't be broad carve-outs of abortion coverage in the Patient Protection and Affordable Care Act? You just might be a foot soldier in the War on Christians. Appearing, for all the world, to trump up a charge against someone for a tragic misapplication (perhaps) of their faith? It's all good. How does that work?

And this isn't to say that people who kill others in the name of driving spirits out of them should simply walk away scot-free. And as far as I'm concerned, this is a result of something between a woeful lack of understanding of the real world and barking madness. But when we're fairly sure that what's happened resulted from an act of faith (however incorrect and/or misguided) rather than malice aforethought, isn't that what Manslaughter charges are for?