The unrest in Ferguson, Mo., following the shooting death of unarmed African-American teenager Michael Brown, is sparking many discussions. One of them is about the kind of equipment law enforcement agencies have, and use.

Jeff Hynes spent more than 30 years with the Phoenix Police Department. He now teaches at ASU and Glendale Community College and says it’s common for people to stock up on weapons and ammunition following a high-profile incident like this one.