Complete the main storyline. Find the four murder mystery clues written on various walls in Los Santos while playing as Michael. A sound will play after each clue is viewed. Take the submarine and swim out into the ocean with the scuba gear to find a drowned woman chained to concrete on the seabed. Go to Richard's Majestic film studio after 9 p.m. and step into the yellow mission circle. Once in the office look at the letter on the desk. It will lead you to the mineshaft. Use a gun with a flashlight to navigate your way to the bottom of the mine to find Issac's corpse, which will be added to your contacts. Select that contact to apply a black and white noire filter to the graphics.