I believe that an article published on October 26th, 2015 from the New York Times about a recent incident involving police officer, Ben Fields, in Spring Valley High School in South Carolina shows bias because it only focuses on one side of the story.
One of the five principles of ethical journalism is "fairness and impartiality." But by only focusing on one side of the story--the officer's actions--and not the entire story including why the officer reacted the way he did, the authors are showing bias towards one side of the story.
This story turned into a hot topic after a students' video of this police officer went viral. What most of the public doesn't know however and what isn't shown in the video, is that the reason the police officer was present in the first place was because the student was being disruptive in class.
Granted, that doesn't warrant violent force, but the student is portrayed as an innocent and peaceful child in the news but, in reality, she was not exactly "minding her own business."