I listened to some TH's earlier and they confirmed my thoughts. Of course just speculation. However they robbed a 7/11. Did not seem to have a well devised plan for after the attack. I dont think they were funded by a terrorist Group. No Group has come forward to claim resposibility. I think they operated on their own or with some minor help?
I'm not sure they would have required funding anyway, considering they used cheap, readily available bomb making materials and were already living and established here for years. Whether they have ties to any group remains to be seen. It was a year before any group claimed responsibility for the London subway bombing. Terrorist groups may be more reluctant to take credit now a days with the drone program in place, but that's JMO.