Place olives, capers, anchovies and crushed garlic in a food processor and process until smooth. With the food processor on, pour in the olive oil in a steady stream to form a smooth paste. Stir in the lemon juice and season to taste with pepper.
If you place the tapenade in a sterile jar and cover it with a thin layer of olive oil, you can keep it in the refrigerator for up to two weeks.
Makes about 1 cup.