Laneisha Shantrice Henderson, 26, has since been charged with second-degree arson and, because the home is operated by the National Parks Service, interfering with government property.

Why?

...a group of people who identified themselves as her family arrived on the scene and explained that she was a veteran and had been dealing with mental health issues...

Sounds like fellow activists, try to give excuse.

I see worse possiblities for motive:

• she was ultra-Woke, hates MLK's ideal of color-blind society.... or

• she had meant to succeed and escape undetected, at which point, media would (falsely) blame whole thing on so-called "white nationalists" or maybe Trump