Emma Walker was a typical teen.  She was pretty, athletic, a cheerleader and dating a football player; living her best life.  What would make someone want to kill a girl, who had no enemies.

Sources:

https://www.instagram.com/restinparadiseemma/?hl=en

Murder In The Heartland- Season 2 Episode 2

https://abcnews.go.com/US/picture-perfect-high-school-sweethearts-toxic-relationship-ended/story?id=57781208

https://www.wate.com/news/crime/new-trial-motion-filed-by-riley-gaul-in-murder-case-of-emma-walker/

https://www.wate.com/news/man-convicted-of-murdering-emma-walker-denied-new-trial/

https://www.oxygen.com/dateline-secrets-uncovered/crime-news/emma-watson-murdered-by-teen-boyfriend-as-she-slept