Mark Pryor
Hugo Marston, head of security at the US embassy in Paris, France, later London, England:

The Bookseller (2012) [review]

The Crypt Thief (2013)

The Blood Promise (2014)

The Button Man (2014)

The Reluctant Matador (2015)

The Paris Librarian (2016)

The Sorbonne Affair (2017)

Hollow Man (2015) [review]  
True crime:

As She Lay Sleeping: A Shadowy Figure, a Brutal Murder, an Anonymous Tip, Will Justice Prevail? (2013)