The door handle will not allow unlocking from the inside. This is a common problem with the Ford Fusion 2007 to 2012 and other cars. A cheap piece of plastic breaks that connects the lock lever with the door handle. You can roll down the window and unlock from the outside or hold both levers together and pull open from the inside. This is a very simple repair. Go to any of many web sites for auto parts and buy a replacement. I bought a Dorman 81702 Ford/Lincoln/Mercury Interior Front Driver Side Replacement Door Handle
. I popped off the lid that covers a hidden screw inside the recess of the door handle. You have to use a torque bit
to unscrew the screw. I then unscrewed the torque screw holding the upper part of the door panel that is opposite the door hinge. The upper part of the door panel can be be carefully pulled away with moderate pressure allowing access to the door handle mechanism. One more bolt holds the door handle part in place. Pull out the broken door handle part, remove the locking cable and put in the new part. Reverse the process to finish up. The whole process took about 10 minutes.