10-20 illegal immigrants living in a duplex

[Harrison Cook]

So i have been looking at a foreclosure in a suburb of NY.  I went to the property today to see if i could speak to the tenants as it appears to be occupied on the evening when i drive by it.  I asked if i could see the inside after speaking with a man who was returning home from work. he appeared to be a day laborer and spoke poor English.  my Spanish is not very good and after speaking with him for 10-15 mins i was informed that they are paying 3k per month to the current owner and cash and were largely unaware of the foreclosure going on on Friday.  

does anyone have experience with stuff like this?

the place is very dilapidated.  I planned on bidding 70%-less fix up costs but am strongly considering walking away now. any thoughts or opinions would be appreciated