https://cineuropa.org/en/newsdetail/485072

From the review:
"In his third feature for the big screen--after Children of the Night and Don't Kill Me--the filmmaker, born into an artistic family, draws loosely on the Casati Stampa case, in which the Marquis Camillo Casati Stampa di Soncino killed his wife, Anna Fallarino, and her young lover before taking his own life. The crime took place in Rome in 1970 and caused a sensation, not least for the salacious details that emerged about the couple’s private life."

Apparently, a "neo-film soleil"...