Modern fantasy with lovecraftian elements. A man is pulled into a secret origanization of monster hunting cops

[Niko]

I've been desperately trying to find this book for years. I used to own it but must have lost it when I was moving around a lot a few years back. I'd barely started it and never got to finish it. It's plagued me ever since. I cannot remember the name or the author and can't get it to come up no matter how many different ways I try searching for it.

Here's everything I remember. detailed spoilery stuff! Not much though since I only got to about chapter 3 before loosing this book forever.

It must have been some time between 2008 and 2014 that I found the book in the first place. It was set in the modern day in probably an American city. Something like Chicago.

The cover with bright and actiony. A digital painting of some people showing down with tentacles. I think there's a car in it somewhere?

The opening scene is a man being hunted down and having his head cut open with a sword to and there's some sort of parasite inside.

The main protag sees either this event or some other thing he wasn't supposed to see and gets picked up by a secret organization of supernaturally inclined Cops (!?) that hunt Lovecraft monsters.

I didn't make it terribly far in the book and don't remember much about the characters but the one think about the book I remember the most vividly is that one of the men on the team had copper wiring in embedded in his skin that's initially mistaken as tattoos and he powers his magic by putting batteries in his mouth.

[Andy]

The Monster Hunter series by Larry Correia? Monster Hunter International

[Niko]

My goodness that book sounds so eerily similar to the one I'm looking for! But it's somehow not the right one?! I am glad I know this series exists now though, so thanks for that!

[Aerulan]

Did it use Lovecraft's actual creatures/gods by name or just similar concepts?
The only secret lovecraft-style-monster cops/hunter/etc I can think of is Stross' Laundry Files that starts with The Atrocity Archives I don't recall the opening scene you describe or the battery guy. But they might be worth a look anyway, it's been a long time since I read any of them and I didn't get through the whole series.

ETA Though there is a scene in the second or third chapter where somebody gets accidentally possessed and is described as having luminous worms behind his eyes right before the main character kills him with a fire extinguisher.

[Andy]

Niko wrote: "My goodness that book sounds so eerily similar to the one I'm looking for! But it's somehow not the right one?! I am glad I know this series exists now though, so thanks for that!"

Glad to know I was close... I'll let you know if I think of another possibility.

[Lobstergirl, au gratin]

Niko, are you still looking for this or did you find it?

[Justanotherbiblophile]

Just to clarify:

MHI does NOT have: "man being hunted down and having his head cut open with a sword to and there's some sort of parasite inside"

MC sees/fights boss-turned-werewolf instead.

MHI does NOT have: "one of the men on the team had copper wiring in embedded in his skin that's initially mistaken as tattoos and he powers his magic by putting batteries in his mouth"

It does have lovecraftianesque monsters (and regular ones), and a private (not cops) "secret" organization (although paid via government bounty program).

Additionally, I'd call MHI more gonzo/humorous than is, perhaps, the norm for these types of things.