How can we keep public places safe from attacks?

People look at Microsoft Surface tablets at a shopping mall in Glendale, California, approximately 10 miles (16 km) north of Los Angeles, on December 26, 2012. Retail experts predict the day after Christmas will be among the top five shopping days of the year.

It seems like open spaces that are unprotected gathering places for large groups of people would be the perfect places for an attack. Is there a way to protect people in open spaces?

The standoff between attackers and security forces in Nairobi has us also thinking about the security in open spaces here as well.

In the past few years there have been a number of mass shootings in several open spaces: The Aurora Colorado Mall Shooting, the Gabriel Giffords rally, the mall shooting in Oregon. It seems like open spaces that are unprotected gathering places for large groups of people would be the perfect places for an attack.

Is there a way to protect people in open spaces?

Joining us now to talk about how best to protect public spaces is Jonah Blank, counter terrorism expert with the Rand Corporation.