Is it possible he heard commotion at the door, went to check it out, when he got close they were able to gain entry after kicking it repeatedly, OR, he heard kicking and tanked it open, but either way, once he openedor the door was kicked open, he got shot, fell back, and the intruder stepped over the threshold and went after mom?
Or is it also possible the intruder tried to kick in the front door, it didn't work, so he went to the back, (or there were two of them), got in and shot the dad, then chased and shot the mom and then went after Jayme, but dad survived for a few moments after being shot and staggered to the front door trying to escape, opened it and fell in his tracks?