Catellani and other parents offered their condolences to the families of the victims and the shooter. Now, they say, elected officials need to stand up to the gun lobby and enact tougher gun laws.
"I was appalled this young man was able to buy legally, without any questions, a weapon of mass destruction," Catellani said.
Mayor Daley spoke about gun violence at an event Saturday on the South side. He says it is time Americans 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," Daley said.
The mayor also says he hopes the presidential candidates will talk about gun violence during the campaign.