Combine bread crumbs, mayonnaise, eggs, mustard, capers and brine, lemon juice, Worcestershire sauce, dill, Creole seasoning, garlic, salt, pepper, and garlic powder in a bowl; mix until well combined.
Combine crabmeat and shrimp in a small bowl. Fold into the mayonnaise mixture until well blended. Cover and refrigerate for 30 minutes.
Remove from the refrigerator and form into 12 patties.
Heat oil in a large skillet over medium-high heat. Cook seafood patties in batches in the hot oil, until browned, 5 to 6 minutes per side. Transfer to a paper towel-lined plate and repeat with remaining patties, adding more oil if needed.