Put the bread crumbs in a food processor and process to fine crumbs. Add the carrot juice or broth and puree until smooth. Add the oil, vinegar, garlic,, salt, hot pepper sauce, sugar, and half of the tomatoes, half of the bell pepper, and half of the cucumber. Pulse until finely chopped. Add the remaining tomatoes, pepper, and cucumber and pulse just until chunky.
Refrigerate until cold, for at least 2 hours or up to 2 days. Serve in bowls garnished with capers.
Tip: If using broth instead of carrot juice, reduce the salt to 1 teaspoon.