It's almost Easter so this is a good time to talk about hopping...that's head hopping or point of view (POV) changing. 

Books allow the reader to jump into the mind of the characters. The beginning of a chapter establishes who's "head" we are in. It is not good to change the POV character without a chapter change or a line break. 

This is from chapter 2 in 'Camouflage'; "In and all-to-rare moment of quiet at his desk...Chief Sean Dermott pored over the...case file." 

I want the reader to be interested in the chief. The plot will develop through his thoughts and feelings, and his senses-like what he sees and hears. This is how readers will get to know him and hopefully care what happens to him. It also allows for smooth plot development because there's no confusion over which character we're following. 

If you're a writer and you feel the need to change the POV before a break-it might be because the character you started with is not the best one to tell this part of the story.