Couple things popped into my mind--one, since Riley is really young, it could just be a weird puppy phase. Lots of dogs go through a stage where they act like human babies "making strange". Tends to be a bit younger than Riley is though.

The other thing is that this is what Preacher acted like when he first started to loose his sight. At that time, Preacher could see just fine in bright light, but in any shadow or darkness, he couldn't see. He is a fairly protective dog so when he sensed something or someone he couldn't see, he barked at it like he would an intruder. As Preacher adjusted to going blind, it stopped. Preacher is now completely blind and has adjusted beautifully. He behaves like a sighted dog and barks like one too! Preacher has a condition called Progressive Retinal Atrophy. It's genetic, irreversable and untreatable, but causes him no pain and has no effect on his lifespan. I just can't rearrange my furniture anymore--that causes him pain when he bonks into stuff!

I'd get Riley's eyes checked and a blood panel. Unexplained, out of character behavior is often linked to low thyroid levels...another Preacher problem that is easy to manage.