Recently, the downtown area has been afflicted by so-called "gangs." I have lived in Springfield all of my life, and have never felt threatened by gangs or violent crimes. The gangs that reside in the downtown area are mostly high school kids who want to feel apart of something. They usually intiate fights with each other, and keep strangers and the public out of it. The best thing to do is just call the police. However, that's one big problem with Springfield; it takes the police 30+ minutes to respond to reports of public fights and disputes. The police force in Springfield is too focused on drinking and driving (which is a problem, don't get me wrong) as well as the local pot smokers to respond to things that are an imminent threat to public safety.
I've had to call the police 3 or 4 times due to fights in the downtown sqaure area, and once, it took them an hour and 15 minutes to respond. By that time, the fight is over and most participants have scattered. Due to this fact, violent crime has risen in the past few years, and we still have no signs that the police force is trying to do anything to slow it down.
Springfield is a fairly safe area, especially the southwest and southeast areas. It is a good place to raise a family. However, I would HIGHLY suggest locking car doors, as my car has been broken into atleast 3 times now. Sometimes, I just don't even think about locking it. Usually, only loose change is stolen, but I once had a CD player ripped out of my vehicle. If you have anything of value in your vehicle, do lock it if you leave it somewhere for a prolonged period of time.