The second presidential debate, moderated by CNN's Candy Crowley, featured a question and extended discussion on the potential reinstatement of an assault weapons ban. Previously, debate moderators in 2008 and Jim Lehrer of PBS' NewsHour, the moderator of the first presidential debate, had ignored the issue of gun violence prevention.

Introducing the town hall participant who asked the candidates what they would do to limit the availability of assault weapons, Crowley noted that the topic of gun violence is one “that we hear a lot, both over the Internet and from this crowd.”

CROWLEY: Because what I -- what I want to do, Mr. President, stand there a second, because I want to introduce you to Nina Gonzalez, who brought up a question that we hear a lot, both over the Internet and from this crowd. 

GONZALEZ: President Obama, during the Democratic National Convention in 2008, you stated you wanted to keep AK-47s out of the hands of criminals. What has your administration done or planned to do to limit the availability of assault weapons?

Gun violence policy had previously been featured during the presidential debates in 1992, 1996, 2000, and 2004.

The debate focus on gun violence comes in the wake of a wave of mass shootings that have been heavily covered by the media and roughly 30,000 Americans killed by guns every year.