Why didn't the kid just cease his threatening behaviour upon seeing the officer?
The kid caused the situation and also caused his own death.
The video is edited. You can see in the moments before what is shown at the link posted on this thread, that the suspect is yelling and throwing things off the counter at the manager.
There was definitely a need to subdue him. I don’t agree with the use of the taser for 37 seconds, but the whole story is not being reported here.