Greetings Sir,
I am quite familiar with the 421 N Washington property as I have sold two other props in that vicinity. It was recently under contract but the repair estimate scared away the buyer. It is 8 units and in horrible condition. You could easily spend $40,000 per unit there to get it onto great shape: that's $320,000 if you hire licensed contractors, plumbers, electricians, drywall, painters, etc. And it will all need to be permitted and inspected. Rent there for a sweet 1/1 with no parking is going to be $700-800 (before utilities and extras). Not sure if that makes it worthwhile for an investor but I think those numbers are realistic. I believe the Seller accepted a number in the low $100,000's so add that into your basis.
Look at Elena Flats for a comparison. The investor doing that won't make any real profit for a long time. I think he is doing it to save it.
Also, incredibly important, you make the deal (or bargain) when you buy the place, so don't be afraid to lowball folks. There are many people with props for sale for many different reasons, some need the money and some don't. Only way to find out is to write up an offer. Also, every deal is contingent upon the inspection results. What appears to be a deal can vanish quickly if repairs are needed that cannot be seen with the naked eye (i.e. termite infestation, crumbling foundations, etc....)
I strongly urge you to become familiar with COJ.net auction properties and tax deed sales. There are indeed some values to be had there but you need to know the process and have CASH.
Best neighborhoods for you right now(IMO):
Murray Hill, Springfield, St Johns Park, St Nicholas and lots of flipping still going on in Riverside-Avondale-Ortega. I personally would also only buy something you yourself are willing to live in. If we have another crash then you might need to slide into one of your own units to ride it out.
I've sold a lot of multi family and there are some decent properties out there right now but also many way overpriced! You should be grossing 10% before expenses IMO. Any more than that is great, but in my experience you have to go into less comfortable areas where keeping and finding quality tenants is more work.
If you do pursue a specific neighborhood, GET FAMILIAR WITH IT, or else you could lose your shirt!
Good luck!