Two mass shootings over the weekend left communities in two countries shaken. Two gunmen killed 15 people at a Hanukkah Festival in Australia and dozens remain hospitalized.

MPR News guest host Catharine Richert talks about what we know about the shootings, what research says about patterns in mass violence and what these attacks mean for communities processing fear and grief.

Guests:

• James Densley is professor and department chair of criminology and criminal justice at Metro State University and co-founder of the Violence Prevention Project Research Center at Hamline University. 
• Jillian Peterson is a professor of criminology and criminal justice, director of the forensic psychology program and executive director of the Violence Prevention Project Research Center at Hamline University. 
• Rabbi Adam Stock Spilker is the senior rabbi at Mount Zion Temple in St. Paul.