I own a triplex in Baltimore (Bolton Hill) and I would say to certainly be wary of investing in Baltimore in general. I would start by being VERY specific about the neighborhood you choose to invest in as you know from living there that the crime rates truly vary form block to block. My initial analysis into neighborhoods left me with only a handful that I would be willing to invest in, Bolton Hill being the winner.
The property is now cashflowing steadily (despite the utilities being held for ransom as well as a couple of permits I am waiting on to come through) and the neighborhood has been great. The lead paint thing is an absolute racket as you have to have it done on every unit every single time there is tenant turnover and it really does seem like a scam. But as long as you know this going in and can incorporate the cost into your numbers, it will be fine. My main suggestion would be to find a property management company that knows the eccentricities of the city VERY well. They can be a life saver in helping you navigate the nonsense that comes from the local government, Another consideration is the taxes in Baltimore City. They are OUTRAGEOUS. I found that I couldn't make the numbers work on several duplexes I was looking at, but adding the additional unit on the triplex allowed me to make the deal.
Bottom line, find a great agent, a great property manger, keep the costs of incessant lead inspections in mind, know that property taxes there are absurd, screen your tenants very carefully, pick your neighborhood with great care, and you can make it work. Hope this helps.