Catellani and other parents stood together, holding pictures of their children. They're calling on elected officials to enact tougher gun laws.
"I was appalled this young man was able to buy legally, without any questions a weapon of mass destruction. Dr. Connie Catellani, Mother of NIU Senior
Mayor Daley is also speaking out about gun violence. He attended an event Saturday on the South Side where he said it was time for Americans to figure out why they're killing each other.
"Why is it? Why do we love guns in America? That is not the answer to any issue in our society. But you see far too often violence inflicted upon really innocent people," said Daley.
The mayor says he hopes the presidential candidates will talk about gun violence during the campaign.
