Before news of the shooting in Dallas, protests sprung up, including one in Minnesota, where Castile was shot during a traffic stop.
President Barack Obama made a statement, calling the shooting of the Dallas police a "vicious, calculated and despicable" attack.
The Dallas mayor and police chief addressed the media throughout the night:
In the aftermath of the shootings, guidance came to the New York police department:
NYPD Orders Officers To Work In Pairs Following Dallas Sniper Attack