This is a story by Kaitlyn O'Connor under one of her pen names, Lyssa Hart.
Ranger Lana Eloy of the United Confederation of Planets Intergalactic Rangers has come to the planet Ata Prime in the Kilkain Galaxy on the trail of Sadin Quyz, a serial killer that has murdered more than 100 women of at least 10 planets. He also murdered her partner the previous year.
When Lana arrives on Ata Prime, she is waylaid by the local authorities and taken to the royal palace to explain herself to the monarch, Rex Pimetrius. He doesn't think this is a job for a woman, but Ata Prime is a member of the Confederation, and Lana has every right to seek the criminal on the planet.
After all is said and done, Lana finds herself saddled with Corin Thantos, a tracker that also happens to be the Captain of the Royal Guard. Seven feet of gorgeous muscle slightly wrapped up in leather armor, a tattoo, and a cod piece as his only 'clothing'. (YUM!!!)
As this is a Kaitlyn book, there's plenty of rumination, but not much personal angst, which I like. There is also very nicely written smex between Lana and Corin. Since this is not one of her ménage books, there aren't any group scuffles that have to be sent outside (see 'Wolfen'), but Corin is adorable and protective, even if he does look like a scary ancient warrior (see the cover, it's great).
Nice, short read with an HEA. I liked it a lot and will likely read it again in a couple of years.