It’s not switched willy-nilly though, it’s strongly correlated with race. The “better headline” is “dangerous black perpetrator prone to crime” and “foolish white boy that looks like you and just made a mistake of youth”. Appealing to the racism is what makes the headline “better” (i.e., more affirming to the majority readership).
Describing an 18 year old as a “teen” certainly is a choice. And not one commonly made when the person accused of a crime is black.
The media seems to have no standard on using terms and switches them willy-nilly to net the better headline.
It’s not switched willy-nilly though, it’s strongly correlated with race. The “better headline” is “dangerous black perpetrator prone to crime” and “foolish white boy that looks like you and just made a mistake of youth”. Appealing to the racism is what makes the headline “better” (i.e., more affirming to the majority readership).