Sigh. I'm dot going to cite everything because I don't have all night and I don't care all that much.
First, you see more violent crime in high population areas, generally in cities with 250,000 or more people (and increasing with population). Aurora is 6% the size of Chicago. They aren't even in the same classification. You might as well compare Chicago with Mayberry.
Population
Chicago: 2,851,268
Aurora: 172,945
Second, economic factors are related to crime (of course we all know this). People who live in Aurora are for the most part pretty well off financially (including my friends who live there).
Estimated median household income in 2009
Aurora: $59,844
Illinois: $53,966 <---- state median
Chicago: $45,734
On average, Aurora experiences just 2% of the murders Chicago does and is usually way below the national average. Aurora doesn't have a problem with murder. Not to diminish the deaths of those who died in Aurora, but having zero deaths one year is more likely do to statistical variance than any "policy changes."
Murder per 100,000 persons
Year -
Chicago -
Aurora
1999 - 641 - 9
2000 - 627 - 15
2001 - 665 - 8
2002 - 648 - 25
2003 - 651 - 25
2004 - 448 - 17
2005 - 446 - 13
2006 - 467 - 4
2007 - 443 - 12
2008 - 510 - 2
2009 - 459 - 5
2010 - 432 - 4
2011 - 431 - 2
AVG - 528 - 11
That news article you linked to just sounds like a bunch of people patting themselves on the back for something that might have happened on it's own. I'm glad they were able to take care of the "gang-bangers," but really, they aren't facing the kind of massive, deeply entrenched crime that Chicago does.
I'm sorry Will, but if you had actually been to Chicago or Aurora you would see how silly your statements are. You'll just have to take my word for it. Aurora is mostly shopping malls and office complexes. You just aren't going to see the kind of crime comparable to Chicago's inner-city. Crime is so widespread in Chicago that, like I mentioned above, even the good parts of town aren't really "safe." You can be waiting for a bus or cab in the ritzy North Loop area and still get knifed if you aren't careful.
http://www.city-data.com
EDIT :
Just for kicks, here is the data with regression. After looking at this I'm less convinced than ever policy is having any effect. Apparently both policies are reducing murder. Or neither of them are. I suspect rates are just following the national average.