thank you so much garen wintemute with the uc davis violence prevention research program. you so much for your time around this very important issue. >>thanks >>for having >>me. >>thank you. this week, demonstrators are hitting the streets of chicago during the democratic national convention. and while law enforcement say that they're committed to keeping the peace. history reminds us that political conventions can be a recipe for chaos. cbs is mark strassmann spoke with some veterans of the 1968 protests about what they hope to see at this convention this week. reporter mayhem on michigan avenue outside the 1968 democratic national convention, mayor richard daley's police thumped protesters in downtown chicago. they jabbed nightsticks into stomachs and skulls. we were demonstrating and it was basically an attack. you can see michael james, now 82, in this famous photograph protesters surrounding a police van. the myth has persisted over the years that we tipped it over. we did not. we rocked it. was it scary terrifying. in 1968, bill ayers was a leader in students for a d