Boehm said some of the most secure malls in the world are in Israel. "They are the experts in dealing with terrorist attacks, bombings, suicide bombings," he said. "And they have used what they have learned after all these years, and they have come up with a great form of security—layers of security. And they've implemented this type of security at many locations, including large malls."

The premise of the Israeli strategy is to keep a terrorist or shooter out of the mall by having layers of defense—from security checking cars and bags, to officers positioned at mall entrances and exits, said CBS 2 NY. Many of the malls in Israel are built with only a few entrances and exits, whereas malls in the United States have dozens of doors, leaving them more vulnerable to attacks.

"One of the reasons that these mall incidents are happening is that (the shooters) want to create mass hysteria," noted Thomas Ciccone, a retired Newark police officer who is now the security director for Christie's art gallery at Rockefeller Center in Manhattan. "When you're talking about a place like a mall, that's the biggest challenge. It's the softest target."

Police and high-end security personnel receive extensive training in spotting suspicious behavior or identifying people who may be carrying weapons, said NJ.com. But, Ciccone added, mall security officers are trained to do the "bare minimum" and are paid little better than minimum wage.

Even if malls spent lavishly on security—installing metal detectors and wall-to-wall cameras—owners would have to weigh that against creating a climate of fear in their shopping centers, said NJ.com.