I used to work with the Air Marshals (part of TSA). By statute TSA is not looking for drugs so if any is found the case is turned over to the local police. TSAs only interest is if you tried to "artfully conceal" (intentionally hide) the drug in any way. Otherwise you usually just get a warning letter.
TC it sounds like you were going through customs which is part of CBP. CBP can arrest you for drugs but they're usually interested in trafficking amounts. Unless you went to a federal facility and spoke to the DEA, the federal government really isn't interested either. They may fine but not prosecute if they're interested.
If you went to jail it was an issue for local police. In California and other states, local police do not persue marijuana charges at the airport. If you're travelling to a state where weed is illegal they may make you dump it though. Sounds like the local police you encountered do have an issue with weed but I wouldn't worry about the feds. Hope everything works out for you.
In all honesty after witnessing how the Texas jails are Id rather this be federal. Most messed up jail system ever. 35 people in a holding cell clearly marked for max occupancy 21. Both toilets clogged not working and overflowing, no water no phones no mats to sleep on the food was cold pop tarts ---