At least four people were killed and 14 others were wounded in a drive-by shooting in Chicago overnight.

Witnesses described the scene as a war zone.

Police say the attacker fled and no one is in custody.

Despite this horrific shooting, the city of Chicago saw a historic drop in homicides in the first half of the year.

That's a trend that's largely been mirrored nationwide.

So for a deeper look at the state of violent crime in the U.S., I spoke earlier today with

Jeff Asher.

His real-time crime index compiles data from hundreds of law enforcement agencies nationwide.

Jeff Asher, great to have you back on the program.

Let's talk about this event in Chicago overnight.

Horrible drive-by shooting.

People see headlines like that, and they certainly are led to believe that we are in this violent crime spiral.

Help us put these kinds of events into context.

Well, it's very difficult.

First off, you don't ever want to downplay the tragedy,

downplay the horror.

Even when you're talking about dramatic declines

in gun violence, dramatic declines in murder,

you're still talking about too many of these incidents,

too many of these tragedies.

That said, it's difficult for people, I think, to put these things in context because very rarely or never do you see a story, there were no shootings yesterday, there were no murders

yesterday. It's only in the presence of these tragedies that these things come to media attention.

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