I can understand an initial arrest. I suspect the rest of the article regrading the charge is likely uninformed. They would have to do an investigation to already declare it a murder charge. I doubt they have done that yet, though they probably have questioned him, and if he was smart he already has an attorney telling the questioners to pound sand.
This kid unfortunately will be the next George Zimmerman. He is alive but its gonna be costly.
There is an earlier video of this kid offering assistance to people as a medic.