You don't get this mission until you take out the hitmen for Salvatore.

You head on out to the ghost town. Note that there are flowers in the graveyard :) The cops show up and bash one of their fellow cops with a shovel for being the snitch. Frank is going off to get drunk leaving you behind with the other cop, Pulaski (and of course the one that was shovel-bashed).

You start digging the hole to bury the bad cop (well the good cop) and are told by Pulaski "It's big enough for two". You try to tell him that he's being used. The other cop (the shovel bashed one) gets up again and Pulaski shoots him. Pulaski now takes off in a car. Why did he take off? Why not shoot you like he was supposed to? Anyway, hop into the supplied buggy and give chase. Note that we've tried to blast him with ammo before he got into his car and it never seems to be enough to hill him.

Somehow you and Pulaski can talk to each other during this wild car chase. Pulaski says that he always wanted to kill you and makes rude comments about your sister. He then goes on to harass you about your mom, too. You have to run him down and bash his car in. If you get yyour hands on a motorcycle that works well. Finally you have a cut scene of him leaning against his car. His last request is to screw your sister, and then you shoot him.

mission passed

Cell phone call - Rosenberg calls and is all upset. He says Salvatore might whack him at any moment.

Grand Theft Auto San Andreas Walkthrough