Doctor Radar written by Noel Simsolo and art by Bezian
In 1920's Paris, a series of deaths has only one common thread--the dead men are all scientists working on space travel. The famous detective and World War I flying ace Ferdinand Straus (who is French despite his name) makes the connection and assumes they are all murders. The French police aren't interested until another victim turns up. The perpetrator is Doctor Radar, a mysterious figure with his own motivations. The battle of wits between Radar and Straus is on.
This graphic novel owes a lot to the film noir tradition. Space travel is a MacGuffin, because the story has no other science fiction element. The characters use a lot of disguises and chases and fights, with no real resolution at the end. There's probably a volume two coming.
Unfortunately, the art is too stylish, making it hard to tell some characters apart. The plot is interesting enough but not outstanding. The characters are not very well developed. I am not interested in reading volume two.