My mother's house has a door similar to that. It has the bars and glass, so you cannot reach through. I doubt she opened this door. So, either he came to disable the camera before using the door, or someone else let him in, not NG. I don't know where I saw it mentioned that NG came in through the garage, but what if someone who had been in the house knew that she always uses the garage door and that person unlocked the front door? She likely would have expected it to be locked and didn't check it before going to bed. My mother never used the front door, but occasionally, one of the kids would open it and it would have remained unlocked. She never thought about checking it, but then she left the back door unlocked while she was gone. It used to drive me a little crazy.