Last night, a lone gunman opened fire on country music fans at the Route 91 Festival in Las Vegas, killing more than 50 people and injuring hundreds more in the deadliest shooting in U.S. history.

The shooter has been identified as 64-year-old Stephen Craig Paddock, a retiree living in Mesquite, Nev. The Associated Press reports Paddock killed himself before police entered his room on the 32nd floor of the Mandalay Bay Resort and Casino, where he shot from a window after breaking the glass with a “hammer-like device.”

On AirTalk today, Larry and a panel of guests will examine White House response, what this means for the country’s ongoing gun control debate and how this will change law enforcement and security measures at future events.

Guests:

Latest from Las Vegas:

Kate Mather, Los Angeles Times reporter covering crime and policing; she tweets

Sergeant Ryan Kroeker, Bakersfield Police Department

The White House response, and is gun control the answer?

Ange-Marie Hancock-Alfaro, professor of political science and gender studies at USC

Jack Pitney, professor of politics at Claremont McKenna College; he tweets

Your calls: Were you in Vegas over the weekend?

Call us at 866.893.5722.

What we can learn from the 1966 University of Texas Clock Tower shooting?

Maria Haberfeld,  professor of police science at John Jay College of Criminal Justice; she specializes in police training

Tim Williams, retired LAPD senior detective supervisor (Robbery-Homicide Division), 1974-2003; owner of T.T. Williams Jr. investigations

Christopher Dergregorian, partner and COO of Omni Sentry Security, a full-service security firm located in Van Nuys

Don Kester, director of training and education for the National Tactical Officers Association, a non-profit that trains law enforcement professionals on how to deal with tactical emergencies, including active shooter situations

Richard Strader, vice president of security and public affairs at the Hard Rock Hotel & Casino in Las Vegas; he was a sergeant with the Las Vegas Metropolitan Police Department for 24 years

Primer: What is domestic terrorism?

Seth G. Jones, director of the International Security and Defense Policy Center at the RAND Corporation where he specializes in counterinsurgency and counterterrorism

Hal Kempfer, retired Marine Lieutenant Colonel and CEO of KIPP knowledge and intelligence program professionals; he does counter terrorism training with government entities around California and Las Vegas