Well, a priest may mention it because the death of a youth is a disturbing event, and the turmoil it created in our nation has been great due to the racial implications it carries, as well as the fact that it points its finger at the so called right to bear arms and to a very controversial law in the state where the tragedy took place.
Our priest mentioned it (mind you, we are in South Florida). He did not express any opinion on the matter, but rather invited the congregation to pray so that peace and mutual love may prevail over evil.
My city has been place of disorders in the past, so there was concern for this. On that day, I was wearing my crucifix outside of my shirt on public transit, and I noticed many, many others wearing their religious symbols in a similar way. It was reassuring to see that people were spontaneously raising their hearts to God in a plea for mercy and peace. I am not aware of any disturbance, exception made for a pacific public demonstration a few days later.