Location: this mission becomes available some time after the completion of the Surreal Estate side mission. Visit the estate in Rockford hills again (the one which you have set on fire in the previous mission). Approach Josh, who will publicly accuse Trevor of the fire and alarm the police who accept the notification. If you want to complete this mission in 100%m you need to shoot Josh (the above screenshot). Apart from that, it would be a good idea to deal with the police also, because they can otherwise respond with fire.
Quickly, run up to the police car parked next to the villa (Police Cruiser), get into the car and start escaping. There is a three-star pursuit to shake off, so you need to make sure that you get sufficiently far away from the site in the first place. Then, find some tunnel or an underground parking lot, thanks to which you will also lose the police chopper, apart from the regular police units.
Rewards for the completion of the mission: none
Requirements for the completion of the mission in 100%:
- Dirty Rat - You need to murder Josh.
- Hot Pursuit - You need to leave the site on the police car.