There have been tons of documented TSA thefts since they started screening all bags. I would definitely file a police report and with the TSA. Based on recent problems with the TSA, I would look to them for the responsibility.
Also, be sure to check the local pawn shops around your point of departure in OMA. Chances are that the person who took it is stupid enough to try and get quick cash for the items. If you have a photo of any of the items, those would be helpful, but if not, and it's realistic, I'd pay a visit to all the area pawn shops and act like a shopper. If you see your items, immeidately notify the shop they are in posession of stolen goods and call the police.
Truly sorry to hear of your loss.