According to its information, while GSR was found on RE's hands, none was found on the things that NE touched - the car keys, steering wheel.
Why don't we believe any of this?
(1) Because, as I understand it, the GSR on RE's hands is minimal, and could be explained by her being shot. Maybe even NE put her (dead) hands around the gun to shoot Baby Lillian. (But wasn't there evidence that Lillian was shot first?)
(2) Because, I seem to recall, GSR was found on one of the knives in the knife block -- which NE claimed he had handled when thinking of killing himself.
(3) Because NE's behaviour just doesn't ring true, even for someone freaking out after discovering their wife has killed herself and their baby.
It follows that NE must have cleaned himself up well after the shooting and got rid of the GSR. How easy is that to do? Will just a quick soap and water do it?