A couple from English author Mark Pryor, both with a Paris setting.
Both books are from Pryor's Hugo Marston series, a series that I've read and enjoyed the first four from. Marston is part of the security detail at the American Embassy in Paris.
Thoughts on the first few I've read below.
1. The Bookseller (2012)
2. The Crypt Thief (2013)
3. The Blood Promise (2014)
4. The Button Man (2014)
The Reluctant Matador (2015) is the fifth in the series, with these two the sixth and seventh. There's another one out which was published earlier this year - The Book Artist (2019).
He has also penned a couple of novels - The Hollow Man (2015) and Dominic (2018) - about a psychopathic prosecutor which are set in Texas where Pryor resides and works as an ADA. Hopefully the books aren't autobiographical!
The Paris Librarian (2016)
Hugo Marston's friend Paul Rogers dies unexpectedly in a locked room at the American Library in Paris. The police conclude that Rogers died of natural causes, but Hugo is certain mischief is afoot. As he pokes around the library, Hugo discovers that rumors are swirling around some recently donated letters from American actress Isabelle Severin. The reason: they may indicate that the actress had aided the Resistance in frequent trips to France toward the end of World War II. Even more dramatic is the legend that the Severin collection also contains a dagger, one she used to kill an SS officer in 1944. Hugo delves deeper into the stacks at the American library and finally realizes that the history of this case isn't what anyone suspected. But to prove he's right, Hugo must return to the scene of a decades-old crime.
The Sorbonne Affair (2017)
Someone is spying on American author Helen Hancock. While in Paris to conduct research and teach a small class of writers, she discovers a spy camera hidden in her room at the Sorbonne Hotel. She notifies the US Embassy, and former FBI profiler Hugo Marston is dispatched to investigate. Almost immediately, the stakes are raised from surveillance to murder when the hotel employee who appears to be responsible for bugging Hancock's suite is found dead. The next day, a salacious video clip explodes across the Internet, showing the author in the embrace of one of her writing students - both are naked, and nothing is left to the imagination. As more bodies pile up, the list of suspects narrows; but everyone at the Sorbonne Hotel has something to hide, and no one is being fully honest with Hugo. He teams up with Lieutenant Camille Lerens to solve the case, but a close call on the streets of Paris proves that he could be the killer's next target.