Brian Moser - 15 years?!?

A lot about original sin messed up the timeline of the show for me, but I will admit it had much more of the OG Dexter vibe than new blood ever did and I enjoyed it! But the main thing I’m confused about: Brian has been killing these people in OS. All of the people he thinks kept him from Dexter. Harry doesn’t arrest him because he doesn’t want the secrets to be revealed (or cause he knocked him out IG but I don’t think he was gonna take him in anyways). So he’s gotten away with it Scott free. Does he continue to kill for the next 15 years and then become the ice truck killer? Or does he go dormant and then start back up? I feel like he has to keep killing…

Also, has been been stalking Dexter and then Deb for 15 years?! Because we saw him stalking at the end of the last ep. So when he goes to date Deb, he’s already been watching her for 15 years. HOW CREEPY IS THAT!!! Why did he wait so long to make contact? If Harry dies when Dexter is 20, I would assume it’s pretty soon after the ending of OS. So why wait 15 more years to make contact with his brother he so desperately wanted to talk to???

I hope we get a season 2 of OS to get these questions answered!