part to close the loopholes his son had ironically pointed out weeks earlier. >> that he was killed with a gun purchased through one of those loopholes. >> in colorado, background checks are now nearly universal. there is a limit on magazine size. but still no one has found cure to america's school shooting plague. >> we have to deal with this terrible illness that we have. guns are a part of that. >> even if you fixed all of the gun loopholes you might not solve the school shooting problem. >> no. we have to do a number of things to deal with the gun violence problem. we will have to compromise, sit down and talk this out and not scream at each other. >> he is still wearing his son's sneakers. >> i like to think by stepping into his shoes that i'm doing what he would want me to do.