Bars on windows - you need confirm with city code if violation they could be consider a fire hazard.
Lynn911 Dallas Realtor & Consultant, Loan Officer, Credit Repair Advisor
The Michael Group - Dallas Business Journal Top Ranked Realtors
The Nichols Way neighborhood does not have a historical high crime rate (as least over the past few years). You can check the Irving PD website for more detailed information. The bars were more than likely installed in the 80's or 90's when crime was a bigger problem in Irving.
As for your concern about safety, the best source is talking to some of the neighbors are how quiet the neighborhood is. I live very close to this neighborhood and can tell you that it is very safe and the neighbors take pride in home ownership.. Good Luck!
Checking with the local authorities may clarify thing for you. I would speculate that if multiple homes in a close proximity the your subject home have take the same percaution, it would be a good idea to pay attention to the message that's being sent.
Before buying, always be on the safe side and follow through on your suspicions.......
I would check with the local police dept. or a local realtor. Either one can give you a run down on the areas crime rate and be able to set your mind at ease. Also, check with people who live in the neighborhood and get there perspective of the area. Main thing is, gather as much information as you can and educate your self, then make a decision based on that information. Buying a house is not something to jump into without all the information.