Apartment 3c
In the movie Scarface, Tony Montana's friend is killed by a chainsaw in his bathtub, this house is located in Miami. In Vice City, the fake-Miami, there's such an apartment, too, with a bathroom. Inside everything is full of blood, besides, it seems that there is a case of drugs in the bedroom.
You can find this low building to the south of Pay'n'Spray in Ocean Beach. It has a pink roof and on its south side there are stairways. Take the right, and go through the black, nonexistent door.
Of course you can find the mentioned chainsaw in the bathroom!