I'm from Rochester NY originally and spent the first 25 years of my life there up until recently. The reason the cap rates are so high are because rent's are reasonable and the property values are very low. I have a SFR college rental and my parents have another, they are making approximately 20% cap rate.
As for areas to invest, down by the U of R is a great area (19th ward) with decent prices (decent duplexes for ~80K). My property is in Brockport NY, however I've been watching the 19th ward for the past several years.
If you look at some of the 30K - 50K multi-family properties in the NW side of the city you'll probably see decent cap rates there, but you'll be dealing with a much worse part of town. Over by Ave A and Ave D is where a great majority of the shootings and crime is. I would advise against that area unless you cant avoid it.
Another place worth looking at would be East Rochester. I grew up a few towns over and have had my eye on those as well. The houses are fairly inexpensive, but in good proximity to some of the nicer suburbs (Pittsford, Fairport, Penfield). Best of luck.