Squatter occupied REO. Difficult to evict?

[Andy Kaye]

I am looking at a Los Angeles SFR, and it is owned by Bank of America. Apparently a squatter has been living in the house for the last couple years, and they are unable to kick him out.

How is it possible for a squatter to dodge eviction for so many years???

What are my risks if I buy this house? My logic is that if even BoA can't kick out this squatter, then I am not going to be able to either.

Any thoughts?