As millions descend on shopping malls for holiday shopping, few may notice new security measures intended to prevent violence like the shooting at a Paramus, N.J., mall that left a gunman dead and terrified thousands of shoppers, the New York Times reports. Shopping centers have been the target of attacks like a shooting last December at a mall near Portland, Or., that left three people dead including the gunman, and the coordinated attack in September on a mall in Nairobi, Kenya. With multiple entrances, parking levels and webs of corridors, the design of a mall provides an assailant with endless opportunities for cover. Public shootings are increasing at an alarming rate, says criminal justice Prof. J. Pete Blair of Texas State University. In 2001, researchers identified five shooting events n public places like malls or schools. Between 2009 and 2012, the number tripled to about 15 a year. Blair has counted 13 in 2013. Mall operators have added to security staffs; installed shatterproof windows and bomb-resistant trash cans; and expanded closed-circuit television security systems. Malls increasingly invite local emergency response teams to speak to their staffs and to use the facilities after hours for practice drills.