Byrd made a rookie mistake.
Missouri has a castle doctrine.
Missouri’s 2016 law states: A person may, subject to the provisions of subsection 2 of this section, use physical force upon another person when and to the extent he or she reasonably believes such force to be necessary to defend himself or herself or a third person from what he or she reasonably believes to be the use or imminent use of unlawful force by such other person. The law also says: A person does not have a duty to retreat from a dwelling, residence, or vehicle where the person is not unlawfully entering or unlawfully remaining.
To read the full law visit here.
Read more at:
https://www.kansascity.com/news/politics-government/article274401285.html#storylink=cpy
Byrd forgot the basics:
Make sure there are no living witnesses to contradict your version of events.
He left the kid alive.