Social media gives insight into Washington state school shooter

A student who witnesses say was the homecoming prince opened fire in his high school cafeteria, killing a young woman and wounding four other students before turning the gun on himself.

Three of those students are in critical condition Friday night - all with serious head wounds. CNN is learning more about the shooter who is said to be freshman Jaylen Fryberg. Students say he was very popular, played football and was recently named to the homecoming court.

So what made him commit this heinous crime? CNN's Kyung Lah digs into his social media profiles, which show a much more troubling side.