Of many differences between life now and life in the 1800s, the speed of communication is the most dramatic.
Answer:
To show reference, and similarities in cases. Other cases may even be relevant to current cases. They may also, do so if they think the unsolved case could have something to do with the current suspect of a case.
Answer:
It can distract people.
Explanation:
Like on the road or may cause them to run into people because they are staring at their phones.
Sternly, maybe could just be grim ( formiadable, harsh, uninviting, depressing, lack of humor, etc)