What to know about the deadly mass protests in Iran and the potential U.S. response

Amid the mass protests in Iran, two sources have told CBS News at least 12,000 people have been killed in the regime's crackdown. President Trump spoke about how the U.S. plans to respond, telling "CBS Evening News" anchor Tony Dokoupil, "we will take very strong action" if Iran hangs protesters. CBS News contributor Joe Zacks, a former deputy assistant director of the CIA, breaks down what to know.