Pretty simple stuff: simple random samples of the products in question. Send them off to independent labs for testing (blind). Produce the results in the case. Then make a ruling. No need for jury trial: the lab results would speak objectively to the case. Too much heavy metals? They lose the suit and the baby food manufacturers should be required to pay restitution and for the legal fees of the plaintiffs. Below acceptable safety levels? There is no suit. The plaintiffs should be ordered to pay for the court costs.