When I look at this video, I see a person exploring the home. They are cognizant of being seen, hence the ski-mask and they are aware of DNA, hence the gloves, or layers of gloves. They are bundled up, way beyond what a person from a colder climate would wear when its 30F, so a local. They don't see well at night, so they have this mouth-activated light and need it to navigate the step (it was moon-bright, that night and the perp leaves shadow its so bright). However, they don't seem to be prepared to deal with camera, but they quickly improvise. I think they have experience breaking into homes. While Nancy may have been targeted due to her family, to me its equally likely she was targeted because her house was dark (the porch light isn't on).