At the AC360 town hall on guns, former FBI profiler Mary Ellen O'Toole explains the factors that indicate a violent person is mentally ill.

People with deeply personal reasons for their gun positions speak passionately about loss, survival, hope, and prevention.

Anderson Cooper talks to Virginia Tech shooting survivor Colin Goddard, Natl. Director of the NRA School Shield Program Fmr. Congressman Asa Hutchinson, Veronique Pozner whose son Noah was killed at Sandy Hook Elementary and Joe Zamudio who helped subdue the gunman in Tucson, Arizona.

During AC360's town hall on gun violence, Cheryl Olsen, Sandy Froman, Dr. Sanjay Gupta and Dan Gross discuss the challenges of diagnosing and treating kids with mental illness.

Liza Long, author of a blog post that went viral after the shooting in Newtown, talks about her personal experience raising a child who struggles with mental illness.

NRA board member Sandy Froman, who opposes universal background checks, debates Dan Gross from the Brady campaign during the AC360 town hall on gun violence.