(CBS News) Congressman Ed Perlmutter, D-Colo., who represents Aurora, said gun laws must be addressed, including the assault weapons ban, which expired in 2004. However, he said this is not an issue for the president but for the Congress. You know, should we reinstate the assault weapons ban? I think we should, and I think that's where it starts," Perlmutter said on "Face the Nation." We ought to be taking a look at how this guy was able to accumulate so much ammunition. He had enough ammunition for, like, a small army. There's something wrong about that. In a previous segment on "Face the Nation," New York City Mayor Michael Bloomberg said President Obama and Republican candidate Mitt Romney should define their positions on the assault weapon ban, but Perlmutter said the mayor's focus is misplaced. NYC Mayor: Hold Obama, Romney accountable on gun control Aurora police chief: No other "person of interest" Aurora mayor: Some victims in "bad shape" I think he's putting his finger on the wrong spot. This is a Congressional issue," Perlmutter said, promising to keep the issue in the spotlight in Congress. I don't think we can avoid it. Carolyn McCarthy from New York, you know, has been a big advocate in this arena, and I'm going to be with her," he said.